How to block outgoing emails with attachments larger than 25 MB


How can you block users from sending emails with attachments larger than 25 MB to avoid exceeding Gmail limits?


  • Admin console
  • Settings for Gmail


You can accomplish this behavior on your domain by setting up a compliance rule. Follow the instructions below for set up:

  1. Log in to your Admin console.
  2. On the main menu select Apps > Google Workspace > Gmail > Compliance.
  3. Scroll down to Content compliance.
  4. Click Configure or Add a new rule.
  5. Name your Attachment compliance rule.
    • Email messages to affect: Outbound, Internal sending.
    • Add expressions that describe the content you want to search for in each message.
    • If any of the following match the message:
      1. Expressions > Add.
      2. On the first drop down menu select Message Size.
      3. On the message site amount type: 25.
      4. Click Save.
    • If the above expressions match, do the following:
      1. Select Reject message.
      2. Type the rejection message.
  6. Click Save.