Getting Past The Spam Filter And Into The Inbox

Like most of my blog posts, this one is in response to a question I recently received (and have received many times in the past) from a friend.

Email Marketing continues to be a strong and valuable asset in the hands of any marketer. However, email deliverability or the ability to get one's marketing emails into the inbox of the recipient is a paramount and critical factor.

And similar to how all the search engine marketers are constantly trying to figure out the workings of the Google Algorithm; email marketers are trying to figure out the workings of the ESPs (Email Service Providers) & the ISPs (Internet Service Providers) and their algorithms.

*Note that in this article I'll refer to ESPs universally to refer to both ISPs and ESPs.

What follows is a round-up of some of the more important factors that impact email deliverability. Each is discussed in short form with a link to a credible and thorough article on the topic.

This could be overwhelming to anyone who is new to the topic. Don't feel like you have to do each of these things perfectly… but starting to manage any of these factors where currently you don't manage them at all, is sure to have a positive impact.

Not in any specific order:

Avoid Spam Complaints

It goes without saying that having your emails marked as SPAM is a really good way to communicate to the ESPs that your emails shouldn't make it to the inbox.

Resource: Definitive Guide About Spam Complaints

  1. Make the unsubscribe link EXTREMELY easy to find. In the welcome email consider putting it at the top in line with the welcome paragraph in addition to having it in the footer.
  2. Don't do shady crap to get more email subscribers who didn't explicitly give you their email address
  3. Always send new subscribers a good welcome email that explains WHAT and HOW OFTEN you will be emailing them. If possible also include detail about where you got their email address so they can be reminded they opted in.

Focus on Quality Not Quantity

It feels warm and fuzzy inside to have a big email list. We want to associate big with better but it isn't so.

The number of quality subscribers matters and has a positive affect.

Equally so the number of bad subscribers (anyone who doesn't want to get your emails) matters and has a negative affect.

Focus an equal amount of energy on removing the bad subscribers (or not adding them to begin with) as you do on getting good subscribers.

Don't Buy Lists And If Possible Force Double Opt-In

There is great risk, both short-term and long term to having people on your email list that didn't ask or agree to be there.

The value proposition here is: Add some bad subscribers that MIGHT buy your product knowing that most of them won't which will make it so that long term even your good subscribers will stop seeing your emails.

RESOURCE: Why Buying Email Lists Is Always a Bad Idea

Is the short term gain worth the long term loss?

Also consider:

  • Purchased email lists often contain spam trap email addresses that signal to the ESP that you bought that list and are sending spam
  • You are not violating the CAN-SPAM Act in the US but you are violating GDPR
  • Email marketing services and providers generally have policies against it and can penalize you or kick you off their system.

Don't Send From Free Domain Email Addresses

Don't make your “from” or “sender” address something with @gmail, @yahoo, @msn, etc.

For one you can't use custom authentication (see next section) but think about it… they know you didn't send it. Meaning, if I use my Gmail email for example and send an email out to a list of 1000 people and 300 of those have Gmail addresses; Gmail is smart enough to figure out that that email wasn't actually sent from Gmail.

It says it was sent from [email protected] to [email protected] but Gmail sees that it isn't in the sent box of [email protected]. This looks like phishing and carries enormous SPAM weight.

Use Custom Authentication

Email authentication is basically the process of sending email that is identified as originating from your sending domain. This helps ESPs verify that the email is coming from where it says it is coming from.

Basically is allows your email marketing platform to send verified email on your behalf that actually originating from YOUR domain.

Setting this up requires one of several methods that all require some form of adding or editing DNS records on your domain. Many email marketing platforms have tutorials or guides to walk you through this.

RESOURCE: What is And How to Setup Email Authentication

Avoid Spammy Words and Phrases

ESPs maintain a list of words and phrases that are often associated with SPAM email. The use of these words on occasion isn't likely to have any significant impact on your deliverability but a high concentration of them or frequent use of them will hurt.

Being somewhat familiar with the list will at very least help you know when you should avoid certain words or look for alternative ways to say something.

RESOURCE: Test the Spammyness of your Emails

Don't Use URL Shorteners

Avoid using URLs like or tiny.url or other shortener services. ESPs just see that you are trying to redirect people and that isn't generally associated with good senders.

Your email marketing platform should be tracking opens and clicks anyway so you don't need those shorteners for analytics.

Limit the Amount of HTML

Companies that send marketing and promotional email want it to look very professional, so often they use complex coded email templates with a lot of images.

Using simple code only and as little of it as possible is going to positively impact your deliverability over time.

Don't Use A Shared Sending IP Address

A sender IP reputation, as viewed by the ESPs, is associated with the originating IP address from which email is being sent. Most of the popular email marketing platforms by default will have you sharing a sender IP with other users of that platform.

Often you have to pay more for a dedicated IP address but it is worth it. Do you want your sender reputation to be negatively affected because the other users sharing the IP address do spammy stuff?

Warm Up Your Dedicated IP Address

When you do start using a dedicated IP address you need to warm up that IP address. Warming it up is the process of slowing building up it's sending reputation.

Suddenly sending a lot of email from a new IP address is going to throw up a red flag to the ESPs.

RESOURCE: How to Properly Warm Up An IP Address

Send With Consistent Frequency

The ESPs get concerned when you go from sending email once a month to once a day. Being consistent with your sending volume and frequency will help your sender reputation.

Ask Customers to Whitelist You

In the same way that it hurts your sender reputation when recipients mark your email as SPAM, it may help when recipients whitelist you.

Whitelisting basically means they set a filter or do whatever else is necessary depending on the ESP or email client to communicate to the system that they WANT your emails to get to the inbox.

In addition to potentially having a positive impact on your sender reputation it most certainly goes a long way to ensure that specific subscriber sees your emails.

Ask them to whitelist you, maybe as part of a welcome email and consider providing some instructions for how they can go about doing so.

Remove Bounces

A bounced subscriber or email address is one where the email address is not able to receive your emails. This could be because the email address doesn't exist, the inbox is full, or a myriad of other reasons.

If your email marketing platform is worth anything at all it will have a Feedback Loop that communicates the issue back to the system and automatically marks that subscriber as bounced.

You don't want to continue to send email to an email address that can't receive it. This costs you money and hurts your sender reputation.

Purge or Clean Your List Frequently

So what about those subscribers that haven't bounced, but they just don't engage with your content anymore?

In the last 90 or 120 days or more they haven't opened a single email or clicked on a single link.

If you are hanging on to those contacts thinking that eventually, they will “re-activate” and out of the blue start opening your emails again and buying from you that is wishful thinking.

These contacts cost you money and hurt your sender reputation. Use automated processes often available from your email marketing platform to identify and remove those contacts.

You can always move them into a re-engagement campaign that sends them 1-3 emails specifically designed to “wake them up” and get them to engage with you once again. But beyond a few emails to that end, continuing to send them email as part of your normal sending is foolish.

Check Blacklists

Sometimes bad things happen. Maybe you broke one too many rules or someone hacks your account and does naughty things.

For whatever reason if you end up blacklisted it will have obvious negative impact on your deliverability.

Blacklists are generally 3rd party companies that specialize in identifying and registering naughty IP addresses. ESPs then rely on them to help filter out bad email.

On a regular basis, you should check the biggest blacklists and see if you are on them. If you are, appeal the decision and get removed.

RESOURCE: Email Blacklists 101 – What You Need to Know

Be Compliant With The CAN-SPAM Act

The CAN SPAM Act is a law that prohibits behavior consistent with spammers.

In short, it requires that you make it easy how recipients can unsubscribe and honor those requests. In addition, you need to have accurate and congruent subject lines, and to include the company physical address.

RESOURCE: The CAN SPAM Act of 2003 – Email marketing compliance

Include Your Business Name In the Sender Name

You want email recipients to quickly be able to identify the company that sent the email. While you can and should (per the CAN SPAM Act) include your company name in the body of the email somewhere (generally in a footer) including it in the FROM line is a good practice.

Don't Include Attachments

Just please don't do it. Including attachments is a certain way to hit the SPAM box.

Use Good Spelling and Grammar

Check your emails for good spelling and grammar. The ESPs have learned over time that Spammers tend to have bad grammar and they tend to spell words wrong in an attempt to get past firewalls.

Spelling errors and grammar mistakes are not only bad for your credibility and brand but also can have a negative impact on your sender score.

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