Sadly, mailbox providers have to purposefully set a moving target when it comes to their exact spam filter criteria, due to the ongoing game of cat and mouse they have to play.

If they were too up-front about exactly how they mark things as spam, then spammers would just reverse-engineer their operations. Aside from this, individuals and organizations can add custom spam filtering logic – so if someone on your list has blocked the word “Unicorn”, unfortunately, your newsletter on “Are unicorns real?” will not be landing in their inbox.

This is why there is no perfect method to reach the inbox 100% of the time. But don’t fret, we can increase the odds to get you as close as possible to perfection!

The first thing to discuss is how you can test for deliverability, this will give you an idea of whether you have major red flags in your email that could trigger spam filters. They could also give you easy fixes that could boost your domain reputation and make you a more trustworthy sender. Because many things are hidden, testing will point you in the right direction.

Use third-party tools

You can send your latest newsletter to a third-party tool such as mail-tester.com before sending it out to your list. These tools will give you a score based on how likely your email is to trigger a spam filter.




Some factors this tool takes into account are:

  • Authentication.
    If you’re using a custom domain, easily improve your sender reputation by setting up proper email authentication with methods like DKIM and SPF. You can set these authentication methods up by adding TXT records in your domain’s DNS management.
  • Blacklists.
    These lists contain IP addresses that are known for sending spam. Mailbox providers will take these lists into account to assess your trustworthiness as a sender. You can become blacklisted for following poor sending practices or sending cold emails from a CRM designed to send warm emails (like AllClients). Understand that it is common to see your account listed on a handful of minor blacklists at any point in time, this is not always a cause for alarm as not all blacklists are weighted equally.
  • Body.
    Does your message include broken links? Do you have very little text compared to images? Are you using a URL shortener? All these factors can negatively affect your deliverability.

Make sure you send the same email to the third-party tool as you’d send to your list. If you’re worried about deliverability, you can test every newsletter before sending it out. This way you can test your content for errors and see if you’ve recently been listed on any major blacklists.

Sign up for your own newsletter

Alternatively, you can create several email accounts under different names and sign up for your own newsletter just as your prospects would. Make sure you don’t use email accounts with the same domain as your sending domain, as these results will not be representative of your list. 

You can sign up using several free mailbox providers such as Gmail and Outlook. Each provider will have its own unique algorithms to determine what mail they consider spam. Companies with custom domains can have additional spam filters that may falsely flag your newsletters as spam as we mentioned before, so there is no need to waste money on paid mailboxes.

A bonus to signing up for your own newsletters using several mailbox providers is that you can make sure your emails are correctly displayed in each client. HTML elements such as buttons are widely used in email marketing but can appear differently in different email clients.

One of the many benefits of the AllClients CRM is that they send you a pre-made monthly newsletter each month that you can use! Try it for yourself and sign up for a free trial of AllClients today!

Continue Reading These Related Articles

Try AllClients Today