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Tips to Avoid Spam Filters When Sending Emails


The world of email deliverability can be a frustrating place. Even the most seasoned and rule-abiding email marketers will experience delivery issues and (accidentally) send spam emails.

In this post, we serve up some of our best advice to ensure that your emails avoid spam filters and get delivered to your recipient’s inbox.


Authenticate your email with SPF, DKIM, and DMARC

Email authentication can be tricky, but it’s easiest to remember that authenticating your email verifies that you are who you say you are. Inbox providers, such as Google and Yahoo, trust authenticated email more and are more likely to deliver mail from authenticated email into the inbox. The following methods authenticate your email and prove to the ISPs that your email is worthy of the inbox and not the spam folder:

  • Sender Policy Framework (SPF)– ensures you are who you say you are by comparing the sender’s IP (found in the domain’s DNS record) with a list of IPs authorized to send from that domain.

  • Domain Keys Identified Mail (DKIM)– meeting this standard ensures that the email was not tampered with during transmission.

  • Domain-Based Message Authentication Reporting and Conformance (DMARC)– leveraging the power of both SPF and DKIM, DMARC requires both to pass in order to send and deliver email.

Avoid blacklists and monitor your reputation

Your email domain has a reputation associated with it and if it slips or you send an email to a spam trap email, you may find yourself on an email blacklist. Unfortunately, even cautious and well-intentioned senders may find themselves on a blacklist.

Reduce the risk of ending up on a blacklist by considering some of the following practices:

  • Using confirmed opt-in or double opt-in

  • Implementing a sunset policy to remove unengaged subscribers

  • Using real-time address validation—if somebody enters in a false email (or even a typo) and you send email to that invalid email address, your sender score suffers.

Keeping an eye on your delivery rates will notify you of any signals that you may be on a blacklist.


Monitor email engagement metrics

Tracking your email performance and engagement metrics is the only true way to know if your email program is improving or if some changes are needed. Before you measure though, it’s important to develop some baseline metrics so you have a consistent picture of your email performance.

The following metrics are a good place to start:

  • Spam complaints

  • Open rates

  • Click-through rates

Don’t panic if you start to notice negative trends, but act as quickly as you can. For example, if your open rates are starting to dip, review your subject lines and email frequency as those two variables are likely affecting this metric.


Build your OWN email list

What you say in your emails is incredibly important, but your content doesn’t mean anything if you’re saying it to the wrong or to an unengaged audience. Always avoid:

  • Renting, purchasing, or co-registering an email from a third party

  • Sharing or using a shared list with a partner

  • Scraping emails—if you’re using a robot to collect emails, known as email harvesting, this practice puts you squarely into the spam camp. Don’t ever do it!

Organically building your email listis a long-term play that will benefit your email program. It’s not the easiest or the fastest way, but it’s the most effective.

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