Spam and Deliverability Knowledge Center

Make it to the inbox—not the spam folder using insights from the deliverability experts. Consider this your one-stop-shop to help you understand everything there is to know about spam and email deliverability.

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Expert advice: Why emails go to spam

Get the scoop from deliverability experts on why emails go to spam—and how to avoid it.

Email deliverability cheat sheet

Know your DKIM from your DMARC—and discover what exactly BIMI means with this cheat sheet.

email send and email testing by litmus

Where will your email appear?

Find out which Gmail tab your email is most likely to appear under.

Stay out of the spam folder… for good

70% of emails show at least one spam-related issue that could keep them out of the inbox. While there are a plethora of reasons why emails go to spam—from send volumes to permissions to content quality—these resources will help you navigate your emails to the inbox.

Email Deliverability FAQs

Have a question about email devliverability not answered here?

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How do I check if my emails are marked as spam?

The easiest way to check if your emails are being marked as spam is to use a spam testing tool like Litmus Spam Testing to check your spam or sender score.

Keeping an eye on engagement metrics can reveal other telltale signs that your emails are being marked as spam. If you see a sudden decrease in email engagement metrics—like open rate—that might be a clue your emails are not being successfully delivered to the inbox.

Delivery rate, bounce rate, click-through rate, and spam complaint rate are all key email metrics to monitor that could help indicate if you’re ending up in the spam folder.

There are a number of elements that could impact whether your emails are delivered to the inbox.

  • Authentication: Implementing authentication protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) can help verify your identity as a legitimate sender and improve deliverability
  • Sender Reputation: The reputation of your email sending domain or IP address  influences whether your emails will land in the inbox or spam folder. Consistently sending high-quality, relevant content to engaged subscribers helps build a positive sender reputation.
  • Content Quality: The content of your emails, including subject lines, body text, images, and links, plays a crucial role in deliverability. Avoid misleading subject lines, excessive use of symbols, or shortened links provided by link shorteners, as these can trigger spam filters.
  • Subscriber Engagement: Engagement metrics such as open rates, click-through rates, and how often recipients mark your emails as spam can impact deliverability. Emails that are opened, clicked, and interacted with signal to email providers that your messages are wanted and relevant.
  • List Hygiene: Keeping your email list clean and up-to-date is essential for good deliverability. Considering implementing a re-engagement email program to remove inactive or invalid email addresses regularly to maintain a healthy subscriber list.

Using Litmus Spam Testing, you can:

  • Discover if you’re blocklisted: When you check your IP address and sending domains against common blocklists, you’ll be notified if you’re on any of them
  • Check your infrastructure: Validate that your email is properly authenticated using DKIM and SPF, and ensure your DMARC record is set up correctly

Test against major spam filters: Get your emails scanned across popular spam filters from inbox providers and webmail services, as well as scored-bsed filters frequently used for corporate spam filtering.

While Litmus Spam Testing works with any email service provide, Litmus integrates seamlessly with Campaign Monitor, MailChimp, Eloqua, Salesforce Marketing Cloud, or Marketo for faster spam testing.

Go-to videos

 

Straight Talk: Why Do Emails Go to Spam (or the Inbox)

 

Improve your email deliverability and optimize sends

 

How to use pre-send Spam Testing

Litmus Tip

Spam test your email in Litmus

  • Connect your email service provider (ESP) to Litmus and pull emails directly from your ESP for efficient spam testing.