Warming up your IP address

Like going on a first date, you only have one chance to make a good first impression with ISPs. Successful warm-up starts with establishing a good sender reputation over the first several days of emailing. Let’s use the analogy of someone that has no credit history going to a bank for loan. Since you have no standing, the bank will naturally be suspicious of your ability to repay the loan.

The same basic logic applies to how your IP is treated by the respective ISP filters. You have to establish your reputation as a good email sender before the ISP filters will “give you the loan” - AKA allow you to send your email campaigns without interruption. Warming up your IP address improves delivery performance, establishes credibility with ISPs and maintains your reputation as a legitimate email sender.

So what can you do?

You can start with sending emails to a small, highly engaged audience at volume levels prescribed by the top ISPs during the first days of IP warm-up. After the initial warm-up you can begin to ramp up volume gradually over the course of 4-6 weeks (for high volume senders).

Common pitfalls to avoid during IP warm-up

However, the road to IP warm-up wonderland, as it were, is filled with potential hazards and email marketers need to be aware of these at all times. According to Daniel Deneweth, Director of Strategic Services at Responsys, common pitfalls to avoid during IP warm-up include: low subscriber engagement and high spam complaints, too many hard bounces, and increasing sending volume too quickly.

Here’s how to avoid these common pitfalls:

1. While building sender reputation on your new IP address, send to a small, highly engaged audience. Send your most relevant email campaigns, and send only to people who have opened or clicked on an email message recently. This is critical. By sending to a highly engaged audience, you’ll also be keeping spam complaints and spam trap hits to a minimum.

2. Insist on porting over all suppression files from your previous provider. Any address that hard bounced on your previous platform must remain suppressed. High hard bounce (invalid) rates are the fastest way to trigger filtering and blocking on your new IP.

3. Ramp up sending volume slowly and in gradual increments. At the end of an official IP warm-up period, your sender reputation is nascent. Think of your new IP like a newborn that needs your protection. Jumping to full volume too quickly will trigger blocking and filtering, destroying the reputation you’ve worked hard to build.

Email authentication 101

One definition of the word “authenticate” is “to conclusively establish the authorship or origin of.” That’s precisely what email authentication is all about as it validates and establishes the authorship, or identity of the email sender as a means to combat forgery and fraud.

Vital to the security of your brand, email authentication measures help to significantly reduce the effectiveness of two differing kinds of attacks: spoofing and phishing. Based on their individual policies, ISPs may require some or all of the authentication measures that are available.

These are the key measures of email authentication used today:

SPF: The Sender Policy Framework is an open standard method to prevent sender address forgery. It enables the verification of a sender’s IP address by crosschecking the domain in the “Mail From” line of an email against the published record a sender has registered in the Domain Name System (DNS).

DKIM: Domain Keys Identified Mail provides a method for validating a domain name identity that is associated with a message through cryptographic authentication. It requires senders’ computers to generate “public/private key pairs” and then publish the public keys into their Domain Name System (DNS) records.

DMARC: Domain-based Message Authentication, Reporting and Conformance standardizes how email receivers perform email authentication using both of the well-known SPF and DKIM mechanisms. This means that senders will experience consistent authentication results for their messages at AOL, Gmail, Hotmail, Yahoo! and any other email receiver implementing DMARC.

Feedback loops and Gmail’s list unsubscribe

When setting up accounts, you also need to be aware of feedback loops (FBLs) and whitelisting. Each plays a role in overall email deliverability.

One of the greatest tools we have in managing reputation and email deliverability is feedback from our recipients. Many ISPs provide us with just that via FBLs, which provide a path used by the ISPs to relay information (feedback) they receive from our recipients back to us. When a subscriber clicks on a “spam” or “junk” button, reporting an email as spam, this information is then recorded by the ISP and provided to us through the current feedback loop set up. Feedback loops are offered by many of the wellknown ISPs

You will notice one glaring omission from this list: Gmail. Unlike most major ISPs, Gmail does not offer a feedback loop for processing spam complaints. However, they do make another feature available for senders to be able to collect and unsubscribe recipients who have marked their messages as spam called ‘List-Unsubscribe’ or a more endearing name might be “The Poor Man’s Feedback Loop.” To implement List-Unsubscribe at Gmail, the sender must:

• Authenticate email using SPF or DKIM
• Have good sender reputation at Gmail
• Use the mailto: option with the List Unsubscribe header. The email notifications from Gmail would then be sent to the “mailto” address

What to remember about whitelists

As for whitelisting, it is not a free pass to someone’s inbox. It is rather a declaration to an ISP that you will be sending high volumes of email from a particular IP address.

Here’s 7 things you should know about whitelisting:

1. Whitelisting sets up a sender to communicate with an ISP down the line if needed
2. ISPs (like Yahoo! and AOL) put a greater emphasis on whitelisting and it takes the better part of the ramp-up process before a sender may be eligible for whitelisting
3. Whitelisting is an important component of the initial IP warm-up process, but not 100% required
4. Some ISPs also include the feedback loop program in the whitelisting application. Remember, a feedback loop (or FBL) allows you to receive the complaints from your users and to unsubscribe those addresses
5. Some whitelists allow senders to bypass some (but not all) filters
6. Whitelisting can allow the display of links and images at some ISPs
7. ALL of the same deliverability best practices and rules still apply for whitelisted senders, there is no “free lunch”

Overall, feedback loops and whitelist status offer true transparency into what the ISPs are seeing as a result of your mailings. Utilizing the information available through these offerings will contribute greatly to the deliverability success of any email program, in addition to overall deliverability health.

Email acquisition best practices

Good email deliverability starts at the beginning: when you acquire an email address. And asking for permission and setting expectations are two basics when it comes to email acquisition.

Remember the analogy we used in the warm-up section, about going on a first date? Well before you can go on that first date, you have to get his or her phone number, right? It’s the same principle at work here.

The most significant deliverability problems are the result of problems with the email signup process. While a particularly acute problem for retailers collecting addresses in store, the sign-up process can cause trouble for any business collecting addresses. New sign-ups can introduce major problems into your otherwise well-tended email list.

Back to the analogy, you first have to ask for permission to get his or her phone number.. It’s no different here as you need to ask for permission to acquire someone’s email address. You will also want to set expectations for that first date, yes? Well you want to do the same thing with your email database. You want to set expectations as to what they will be receiving from you going forward.

4 quick tips:

• Require double email field confirmation
• Consider using an email validation vendor to clean out known hard bounces before you send for the first time
• Send a welcome message or series to communicate clearly and reinforce subscriber expectations
• Don’t incentivize sales associates for email signups. This leads to very low quality entry

Tread carefully with new sign-ups

“Sending email to new signups always carries an elevated risk of triggering spam filters, due to the unproven nature of the new email address,” says Daniel Deneweth, Director of Deliverability Strategy at Responsys. For this reason, it’s very important to stay current with your welcome campaigns. The risk of triggering spam filters is compounded if you ever find that you have a backlog of new email signups.

If you find yourself with a backlog of new signups, don’t email to them all at once. This can trigger blocking and filtering. Spread out your sending to these new addresses over days or weeks, keeping a low volume of welcome messages each day relative to your regular email volume. This will help minimize any negative impact to your sender reputation and delivery rates.

The risk of triggering ISP filtering or blocking from poor email acquisition practices comes from the following:

• High hard bounce (invalid) rates
• High spam complaint rates
• Low response, resulting in low subscriber engagement rates
• Spam trap hits
• Volume spikes

Why long term inactive addresses still matter

Now it’s time for us to bust a… no, not a move, but rather a myth dealing with long term inactive email addresses. You may be under the impression that these types of addresses are not relevant when it comes to acquisition.

The truth is, you have to be concerned because people will create a new account and signup with an email address that they long ago abandoned. Additionally, they may make a typo and the resulting email address happens to match a spam trap email address. Plus, consider the fact that the industry average for email address churn is 20-30 percent per year, which means just one year after acquiring an email address, there is a significant chance that address is no longer valid.

Emailing to too many invalid addresses will likely result in ISP filtering and blocking, preventing your email from reaching the inbox. So before emailing to addresses for the first time, perform a list hygiene cleanse with the help of an email address validation vendor, such as LeadSpend or Fresh Address, to identify known bad addresses.

Email address validation vendors have proprietary list audit technology, which helps reduce bounce rates by flagging invalid email addresses, including:

• Duplicates
• Typos
• Formatting problems
• Syntax errors
• Dead domains
• FCC-mandated wireless blocks
• And the DMA’s “Do Not Email” records.

Where possible, they also flag bogus and malicious email addresses, as well as some spam trap and honeypot addresses, to help minimize support issues and keep you off of ISP blacklists.

The wrong way to collect email addresses

As mentioned previously, it’s not a good idea to incentivize sales associates for email signups as it leads to a very low quality of email addresses entered. Here’s why:

• A sales associate misunderstands the correct email address
• A customer gives a fake email address to get the offer
• A customer might not know their correct email address, or provides an old address he or she no longer uses
• The sales associate or the customer mistypes the email address
• The customer doesn’t understand he or she will be receiving promotional email
• Customers who receive any email beyond an eReceipt are often surprised
• Acquiring new email addresses is of course the golden goose for marketers but as Deneweth puts it, there are inherent dangers associated with it

Secrets to new subscriber engagement

Orchestrating your marketing based on customer data such as channel preference and purchase history is what fundamentally drives high engagement with emails. And, the need to keep your subscribers engaged takes on a whole new meaning and level of importance when it comes to the topic of deliverability for, if no other reason, a lot of the major ISPs are looking at and monitoring user-level engagement to determine inbox delivery.

The more sophisticated marketers get in orchestrating individual customer experiences, the more relevant email messages become, which drives more engagement and more inbox placement vs. junk folder placement. Open and clicks and the recency of those activities is often the metric used to determine email engagement level. When those in your database become uninterested and in turn stop clicking on your emails – there can be adverse effects on email deliverability.

The bottom line is that by continuing to send email to unengaged subscribers, you’re putting your reputation as a sender at risk, as well as increasing the chances of an inactive address being converted into a spam trap.

Defining engagement

So how do you define engagement? “Often clients have an internal definition of an ‘active customer’ and ‘inactive customer’ that have to do with website visits, purchase history, customer or account status,” says Heather Goff, Senior Deliverability Consultant at Responsys. “While these definitions make perfect sense from a business standpoint, from a deliverability standpoint they have little bearing. ISPs need to see engagement with email specifically.” ISPs have gone on the record saying that they track user activity in two categories: positive engagement and negative engagement.

Recipient actions that contribute to the positive engagement quotient are:

• Clicking through links
• Adding an address to their contacts or address book
• Enabling images
• Opening the message
• Scrolling through the message

Recipient actions that contribute to the negative engagement quotient are:

• Reporting as spam
• Deleting the message
• Moving the message to trash
• Marking messages as read
• Ignoring messages

How to approach inactivity

The potential downside to these metrics comes in the form of inactivity. Yes you want to put your customer front and center but what if, for example, over half of your distribution list has neither clicked nor opened a single email in one year? That could have major ramifications according to Goff who says she’s seen major ISPs filter ALL the incoming email, even email going to engaged subscribers.

And size does matter. “ISPs tolerate even less inactivity from high-volume senders,” says Goff. “They will begin to send unengaged email recipients to the junk folders from senders with list sizes in excess of one million.”

When it comes to the duration of inactivity, ISPs each have their own tolerances for how long an address can go inactive, but in general any activity inside of 1.5 to 2 years is acceptable. Of course, this recommendation should be tempered by the percentage of the marketer’s list that’s inactive in addition to their sender reputation. If a large percentage of a list is inactive, the acceptable duration of inactivity decreases.

Decreasing the frequency at which inactive subscribers are emailed is a defensive tactic used to boost the level of engagement seen by ISPs, while continuing to give these subscribers opportunities to engage. Once a definition of inactivity is in place, the next step is to make changes in the messaging or frequency as part of a reengagement strategy.

Create a plan for re-engagement

The success of a re-engagement program is characterized by opens and clicks. If inactive subscribers don’t respond to re-engagement efforts, eventually they should be removed from mailing lists because of the deliverability dangers.

As a last-ditch attempt to save inactives from being removed, some marketers may find nominal success by taking the intermediate step of sending a re-permission campaign. These emails ask a subscriber to confirm their continued interest in receiving emails by a certain date or else be removed from future mailings.

“From a deliverability perspective, re-permission campaigns are needed when a sender is being heavily junk foldered (80%-90% or more) at any given ISP for an extended period of time (more than 1-2 weeks) and inactivity or spam traps are the root cause of the junk foldering,” says Goff. “In order to identify the audience that should be sent a re-permission email, a full inventory of actives vs. inactives and business terms and time tables for each must be established.”

Then, it’s important to create a re-engagement strategy that uses changes in email frequency and content to keep subscribers from becoming inactive. And finally, establish rules for removing inactives from mailing lists and consider creating a triggered re-permission campaign to give wayward subscribers one last chance to stay opted-in.

Needto-know deliverability metrics

Most email marketers are familiar with engagement metrics such as click-through rate, open rate, and so on. But, when it comes to deliverability success, monitoring engagement metrics goes hand-in-hand with monitoring the more traditional deliverability metrics, such as bounce rates, spam complaints, sender scores and more.

For example, there are generally two kinds of bounces: soft and hard. Identifying one from the other can provide insights into problem areas and potential root cause of deliverability issues. Another example of a specific metric that can provide email marketers with invaluable insight is open-to-click ratio. This metric helps marketers measure just how effective and compelling their content was for the reader. Moreover, in the eyes of major ISPs, consistent engagement metrics can establish a positive sender reputation and strengthen overall deliverability.

Once an email has been delivered successfully without bouncing, there are additional measures such as understanding delivery of emails to a recipient’s inbox vs. delivery to their junk/spam folder. But that’s just the tip of the proverbial email deliverability metrics iceberg.

There are other metrics to consider such as Microsoft Smart Network Data Services (SNDS), spam complaints and unsubscribes and Return Path Sender Score. The bottom line is to continually monitor, react and adjust to email marketing metrics so marketers may drive a strong sender reputation with ISPs. This ultimately allows marketers to consistently reach their audience and achieve their business goals.

Breaking down bounce rates

Let’s take a deeper dive into a couple of the email deliverability metrics. First, bounce rates. A bounce is when an email is sent, but is then returned with a notice that the message was not delivered. And there are two types of bounces: A hard bounce and a soft bounce. The main differentiator between the two is that hard bounces are permanent and emailing to them should not be attempted again whereas soft bounces are temporary and can be re-tried.

The world would be a much simpler place if all soft bounces were temporary and all hard bounces were permanent. But such is not the case as different ISPs handle bounces in different ways. There are two standard bounce classifications that differentiate between hard and soft:

• Generally speaking, bounces that begin with a 4xx explanation are considered soft or transient delivery failures. This means they can be reattempted for delivery and may still have a chance of being accepted by the receiving domain at a later time
• If a bounce begins with a 5xx code and message pertaining to a permanent failure, then it is considered a hard bounce. Reattempting delivery of these bounces is not likely to succeed and may in fact do further damage to a sender’s reputation.

Explaining spam complaints and traps

Next, the omnipresent spam complaints, which are based on abuse reports received from the ISPs currently offering feedback loops. Spam is figuratively and literally a four-letter word for email marketers and spam complaints are indeed a major factor in determining inbox placement.

The reasons why someone clicks the spam button are numerous, including they simply don’t want to receive your message anymore and for whatever reason don’t click unsubscribe – or because they received an email that was not expected or it came from a brand they did not recognize, nor authorize.

Regardless of why, when recipients hit the spam button, even in small numbers, sender reputation dips, resulting in messages being filtered to the bulk folder, which sometimes results in delayed or blocked delivery.

Mangalapalli recommends measuring your spam complaint rates on a daily basis and also look at 7-day and 30-day rolling windows. “Keep in mind,” he adds, “that not all ISPs report back their users’ spam complaints. Gmail, for instance, does not provide spam complaint data. Windows Live Hotmail/Outlook.com, Yahoo, AOL and others do provide this via feedback loops.“

Under the guise of “one size does not fit all” it is important to review spam complaint rates at each individual ISP in order to gain an understanding of how user behavior and deliverability varies across email providers. One of the most damaging issues for email deliverability and maintaining proper list hygiene are spam traps, and the avoiding thereof.

There are two types of spam traps.

• Recycled spam trap: An old or inactive email address that has been kept “alive” for the sake of catching senders who continue to email non-existent or unengaged subscribers
• Pristine spam trap: This exists for the sole purpose of catching spammers who should never have acquired this email address in the first place. The pristine spam trap never subscribes or opts-in to any kind of marketing communications

Avoiding these spam traps requires diligent monitoring of engagement levels and removing inactive subscribers. Mangalapalli adds that “while any type of spam trap hits are damaging to a sender’s reputation, pristine trap hits are exponentially worse.”

Another email metric marketers should use is Microsoft Smart Network Device Services (SNDS). Specific for email sent to Microsoft’s Hotmail/Outlook.com network of subscribers only, SNDS provides data about the traffic seen originating from unique IPs, such as email volume, complaint rates, and spam trap hits.

One final metric to focus on is Return Path Sender Score, which serves as a helpful benchmark for reflecting how ISPs may view the reputation of your sending IP address via Reputation Monitor. Given that fact 83% of email delivery failures are caused by reputation problems, it is extremely important to monitor your score, which brings together various metrics, sending patterns and trends displayed by the sender and plugs them into a proprietary formula to come up with a score ranging from 0 to 100. Reminiscent of our grade-school days, this can serve as a periodic report card or healthcheck of your email program’s reputation.

What the Gmail changes really mean

2013 brought one of the most talked about moments in the history of email deliverability as Gmail made a significant change to its user interface. The change brought in the use of tabs as a way of sorting incoming email messages. Gmail now sorts email among the Primary, Social, Promotions, Updates, and Forums tabs. Personal messages arrive in the Primary tab, social invites and notifications go to Social, Marketing messages arrive in Promotions, Transactional messages go to Updates, and list email lands in Forums.

“The first thought of many marketers when these changes arrived was one of dread,” says Kevin Senne, Senior Director, Deliverability and ISP Relations at Responsys. “The thought of not being in the Primary Inbox was a thought that ran contrary to everything we’ve been taught about deliverability. The reality of this change has started to become clear as time has passed and in fact, the tabs have proved to be a positive change for marketers. “

Why the new tabs are working

By grouping the promotional messages together in one tab, Gmail has now given marketers an audience with a propensity to buy. When a user comes to the Promotions Tab they are looking for marketing messages. This is a nice departure from the past strategy of hitting the inbox and trying to stand out.

The Updates Tab is also an important place for marketers. This tab contains important messaging normally classified as transactional. Purchase confirmations, shipping notifications, and e-receipts are the types of messages one should expect to find in the Updates Tab. These types of messages continue to perform very well because they have content that people want to see. This also translates to the success of other tabs as consumers are conditioned to explore other tabs to see important messaging.

Despite the evidence that life in the Tab system is good, some marketers still worry about leaving the familiarity and comfort of the Inbox. Many marketers have launched campaigns where they encourage recipients to drag the email to the Primary tab.

The reality is whether you are asking someone to add you to your address book or drag you to another tab, the chances are low that will happen. Gmail adds some complexity to this process when dragging messages between tabs in that there’s an extra confirmation step at the top of the screen that is difficult to see.

5. tips for sending to the tabbed inbox

1. Don’t spend time trying to change how Gmail classifies messages, you are most likely in the correct place – concentrate on the messaging.
2. Pay extra attention to subject lines. The reason being your marketing message is now competing against ALL other marketing messages – ONLY. Consumers are seeing all marketing messages in one place so the need to stand out is even more paramount.
3. Watch your open rates closely, different senders have different experiences, but in all cases traditional deliverability troubleshooting is the way to improve open and inbox placement rates.
4. Transactional messages should be read at a very high rate in the new layout and can be a great vehicle to promote your other programs.
5. You can also teach users to drag and drop messages to other tabs. This can be an alternative to an “add to address book” method.

Understanding international deliverability

Think you’ve mastered email deliverability in the U.S.? Not so fast. Most countries operate differently when it comes to regulating ISPs, privacy, promotional email and more. Let’s say for example you have the ability to create email marketing campaigns in Norwegian. How do you know if the Norway email server will even allow for your email to be delivered? Or what happens if your email in French does get delivered, how do you know if the PC or mobile phone in France correctly displays your message?

“To operate in today’s global environment, marketers need to understand more than just email deliverability in the U.S.,” says Kevin Senne, Senior Director, Deliverability and ISP Relations at Responsys. “You should at least be aware of the privacy laws and regulations in the countries you want to deliver email.”

Knowing how to operate on an international scale is vital, especially when you consider the fact that total worldwide revenues from email will grow to over $12 billion by 2016 and email traffic is estimated to grow to over 192 billion emails sent per day by 2016.

Taking a worldview

U.S. based mailers mistakenly believe that CAN-SPAM is a good base for understanding international email regulations. However, many other countries have much stricter laws governing permission and what is necessary for lawful contact.

Australia is a great example of a place with dramatically different feelings about permission. The Australia Communications and Media Authority (ACMA) takes dramatic steps to prohibit unsolicited emailing. ACMA will take out front page ads in major Australian newspapers to shame violators. Heavy fines are common for practices that are acceptable under the U.S. version of CAN-SPAM.

A good rule of thumb when emailing to domains outside the U.S. is that explicit permission will be required, even with transactional email. Many senders incorrectly believe that “transactional” email is exempt from any repercussions. While transactional email does often fit into different legal categories, as far as receivers are concerned, all email is the same.

“There is no special pipe or identification for this type of (transactional) message. Yahoo! or Hotmail for example see a transactional message the same way they see a newsletter,” says Senne. “This means that you must still build and maintain a strong sending reputation to actually deliver these messages. This is especially true for international domains because the volume is generally smaller.”

The importance of China

Understandably, emailing to consumers in China is becoming increasingly important for many marketers. However, marketers must take time to understand the country’s deliverability landscape in order to be successful.

“It’s very important to understand that deliverability success in China is measured in different ways than most senders are familiar with,” says Senne. He points to open rates as being one area that should be measured differently. “The global open rates of major ISPs are around 25 percent, however open rates are substantially lower in China. So if you have an open rate of say 12-15 percent in China that does not necessarily mean your campaign did not fare well.”

The regulations and real-world requirements for mailing to Chinese domains are also very different from other regions. The technical requirements and permission standards are much more difficult than global domains such as Yahoo!, Hotmail and AOL.

Filtering tends to be setup as you might have expected to see in the U.S. three to five years ago. Generic messages do not tend to perform very well. Be sure to send individually relevant information whenever possible.

Global deliverability tips

Argentina – Explicit consent is required. Argentina has a public do not contact list, the DNPDP that must be honored.

Australia - Explicit consent is a must. Very strong laws regarding permission and data privacy. Australian ISPs are very responsive to consumer issues.

Belgium – Opt-in is required and the sender is responsible for refer-a-friend consent and managing those opt-outs, making this practice dangerous.

Finland – All marketing messages must be clearly marked as advertisements

France – Consent is required for emailing. French ISPs historically accept fewer connections making email delivery times slower.

Germany – Strong laws requiring opt-in. If a recipient opts-out of a mailing, all data must be erased from the sender’s database.

Hong Kong – Expressed consent is required and it must be different from T&C acceptance. Consent must be clearly differentiated and easy to understand.

Italy – Prior consent required for marketing messages. End-user consent is required for cookie use and senders must disclose if any data will be shared with a 3rd party.

Netherlands – Pre-checked boxes are not allowed as a mode of consent.

Russia – There are no current electronic privacy laws. Russian ISP such as mail. ru can be challenging. Having a local presence is very helpful at this time.

Spain – Maintains a government do not mail list.

Japan – All email must contain clear and visible information for sender name and title, correct address for an opt-out (must be at the top of the email) and the sender’s address and phone number must also be displayed.

Canada – The Canadian Anti-Spam Legislation (CASL for short) takes effect July 1, 2014. The full provisions will roll-out over the next 3 years. Explicit permission and private right of action are the most important measures.

Singapore – All messages must contain an unsubscribe link, phone number, and a postal address. This information must be in English. Unsubscribes must be handled within 10 days.

As we alluded to in the introduction, email deliverability has gone through major changes over the past decade. While ISPs have made significant moves to deliver a better experience for users (i.e. the new Gmail interface), marketers have also shifted their strategies away from mass-marketing and toward orchestrating a more individualized experience for customers. This is an important shift and we’re already seeing it have a positive impact on deliverability.

Conclusion

That said, the marketing industry will continue to evolve at lightening speed, making it critical to stay on top of developing trends, regulations and technologies that might affect your ability to consistently reach the inbox. Deliverability can be complex, but if you follow the best practices in this eBook and keep up with industry news (check out the New School Marketing Blog), you’ll be well on your way to success.

There’s more! Here, for your viewing pleasure are six burning email deliverability questions answered:

There’s more! Here, for your viewing pleasure are six burning email deliverability questions answered:

(A) There are hundreds of blacklists being operated by numerous anti-spam activists and organizations. Blacklisting essentially means your IP has been flagged for sending unwanted traffic and the followers of that blacklist (i.e. ISPs) may decide to block your emails. The key is to narrow down the significance of a blacklist based on its ISP footprint.

For example, Spamhaus is an organization that has a vast majority of ISPs subscribing to its blacklist. Upwards of 80% of a B2C marketer’s list could be blocked as a result of being blocklisted by Spamhaus. On the other hand, a very small blacklist may only cover a few private domains with only a handful of subscribers from your list. This blocking impact of this would be much less noticeable, though the root of the issue should still be corrected and mediated if at all possible.

(Q) Can you please explain the difference between blocking, bulking and blacklisting?

(A) There is a very common misunderstanding between these three terms so it is important to distinguish and point out the differences. Blocking occurs when an ISP takes action and refuses to accept your emails. Bulking happens when an ISP accepts your email, but routes the messages to bulk or spam folder vs routing to the inbox. Blacklisting is the act of being flagged as a sender of unwanted email and while ISPs can operate a blacklist, this is most commonly done by independent blacklisting organizations such as SORBS, Spamcop, Spamhaus.

(Q) Any tips for protecting reputation of transactional IP?

(A) ISPs factor sender reputation the same way for both transactional and promotional IPs. The message (content) and relevancy to recipient are what can make the difference in positive or negative reputation. Successful transactional messages are those which the recipient has specifically triggered through a specific action (i.e. purchase, password reset, etc.). In fact, if they don’t receive the message they may be prone to pick up the phone and call your customer support.

(Q) Is ISP remediation still effective these days?

(A) ISP mediation is still very effective, but the definition of what mediation means has changed significantly. As with everything, technological advances and smarter consumers have combined to have a major influence on the email industry. Gone are the old days of calling up an ISP postmaster before a big launch so he or she can let your email through with no questions asked. As the amount of email volumes kept growing, it became too much for the large ISPs to manage manually. The postmaster departments have been downsized and replaced with sophisticated, automated filtering systems. These filters are constantly monitoring all traffic and adjusting based on the ISP specified reputation scoring formulas. They react in real-time to block, bulk or accept messages and the same formulas apply to unblock requests. It is important to maintain contacts with ISPs and follow all established protocols for mediation as needed. The control an individual postmaster has over their systems is minimal compared to years past so the goal of mediation is always to establish root cause by finding out what caused the deliverability issue. Machines don’t play favorites and ultimately the senders following best practices are the ones who are rewarded by the ISPs with good deliverability.

(Q) We have the most trouble delivering to mid-tier ISPs like Comcast, Verizon, Cableone, etc. Why is it so challenging to deliver to these addresses?

(A) One of the main differences with these ISPs is that they are all paid services whereas the majors like Yahoo!, Gmail, and Hotmail are all free services. This means that once an individual discontinues their paid subscription with a Comcast, Verizon, etc. their address is no longer valid. Over time if the marketer continues to send to these expired addresses, they will have a higher hard bounce rate and could also be sending to addresses that have been turned into spam traps.

This results in blocking by the ISP and a constant battle to get back to the inbox until the root cause is addressed. This a common learning experience for many senders who do not use engagement based filtering. The recommendation is to always have a filter that will suppress addresses with no opens or clicks within the past 12-month period… which leads us to the next and final question.

(Q) What’s your view on cold storage? Should we have a strategy for permanently retiring inactives?

(A) ISPs are placing more weight on subscriber engagement to determine sender reputation. This means you need a strategy for older addresses that are no longer actively opening or clicking before they start to hurt the deliverability of your active subscribers. Addresses without open or click activity beyond 12-months should be considered for a re-permission campaign as a final attempt to reactivate the subscriber. If the address still does not respond and opt-in, they should be marked as permanently opted-out.