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Can an email signature cause Spam detection?
Can an email signature cause Spam detection?
MySignature Support avatar
Written by MySignature Support
Updated over a week ago

In this article, we will explore whether email signatures can trigger spam filters and what you can do to ensure your emails always land in the inbox.

Also, we will test how email signatures created by MySignature will pass the spam filter!

Reasons for getting into the Spam folder

Emails can end up in the spam folder for a variety of reasons. Some common reasons include:

Content: The content of an email can also trigger spam filters. For example, using certain keywords or phrases that are commonly associated with spam can cause an email to be filtered. Emails that contain a lot of images or links can also be seen as suspicious.

Sender reputation: If the email is sent from a sender with a poor reputation or a history of sending spam, it is more likely to be filtered as spam.

Email authentication: Email authentication is a process that verifies the identity of the sender and ensures that the email hasn't been tampered with. If an email fails authentication checks, it may be sent to the spam folder.

User behavior: If a user marks an email as spam, the email provider may learn from this behavior and start filtering similar emails to the spam folder.

Can an email signature cause spam detection?

Yes, email signatures can sometimes cause spam detection issues. Here are a few reasons why:

Too much information

Including too much information in your email signature can trigger spam filters. This can include things like multiple phone numbers, social media links, or lengthy disclaimers.

Image-heavy signatures

Email signatures that rely heavily on images can also cause issues. This is because some spam filters may automatically flag emails that contain a lot of images as potential spam.

Non-compliant code

Email signatures that contain non-compliant HTML or CSS code can also trigger spam filters. This is because some spam filters may see this code as an attempt to hide malicious content.

To avoid these issues, it's best to keep your email signature simple and straightforward. Only include the most essential information, and Additionally, make sure your HTML and CSS code is compliant and follows best practices for email design.

Let's make a few tests to ensure that emails that use email signatures created by Mysignature can pass the Spam filter test.

Testing email signatures created by Mysignature

Sending emails with signatures via Gmail, Yahoo, Outlook, etc

We came up with regular email for marketing needs:

  • 2 links in the email body

  • Strong text

  • Emoji

  • Email Signature, which include HTML, links, and images

We use the service Mail-tester to test our emails (462K users per month by SimilarWeb).


As you can see, using an HTML email signature and image in your email has a small impact on getting into Spam.

Sending email campaigns with email signatures via Mailchimp, Sendgrid

Now let's test when you send email campaigns via Mailchimp and Sendgrid and use email signature by MySignature.

We took one of our emails and tested it.


So as you can see, using email signatures in your emails is safe, and your deliverability shouldn't hurt.

But email content is just one part of dozens of factors that can impact to Spam filter. So you need to take your sender's reputation as well.

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