Allow .EML incoming Attachments for a Specific cPanel Account Only

Netgate Unknown

• March 20, 2026 18:50

Hello,

We are currently reviewing the handling of .eml attachments in our shared cPanel/WHM environment.

We came across the following official article:
https://support.cpanel.net/hc/en-us/articles/26318185855511-How-to-permit-eml-email-attachments

Based on this documentation, we understand that allowing .eml attachments requires modifying Exim’s attachment filtering configuration, which appears to be applied globally at the server level.

Our question is the following:

Is there any supported or recommended way to allow .eml attachments only for a specific cPanel account or domain, while keeping the restriction enabled for all other accounts on the same shared server?

More specifically:

• Can this be achieved via custom Exim ACLs or system filters with per-domain or per-account conditions?

• Is there any supported method within WHM (without affecting future updates) to selectively whitelist .eml attachments?

• Or is modifying the global configuration the only available approach?

Our goal is to maintain the current security policies for the shared environment while evaluating whether a controlled exception can be implemented for a single account.

Thank you in advance for your guidance.

Best regards,

• 

  cPRex Jurassic Moderator

  • March 20, 2026 20:14

  Hey there!  This is possible through Exim directly, but this isn't something you'll find in the WHM interface as you'll need to get into custom filters to make this happen.

  There are some additional details in an older post at https://support.cpanel.net/hc/en-us/community/posts/19143547983383-Allow-EML-Attachment-for-Specific-Emails-Addresses-Only but it is still valid information.  I'm not able to directly help with Exim filter customization through the Forums, but that should get you pointed down the right path for this.

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