Specify Max Message Size Limits for Mailing Lists

This article applies to recent versions of SmarterMail. View articles for SmarterMail 15.x and earlier.

To prevent abuse of the mail server and encourage better interoperability with other mail servers, administrators may define the maximum size of email a user can send through a mailing list. Outgoing mailing list message size limits can be set for all domains using Domain Defaults or managed on a domain-by-domain basis, as needed.

When setting the maximum message size, keep in mind that when a message is sent, mail servers automatically MIME encode the message, which will increase its size roughly 35-40%. If you would like your users to be able to send 10 MB messages, you should make the max message size 15 MB.

To set up Domain Defaults:

  1. Click the Manage icon.
  2. Click the Actions (...) button. 
  3. From the dropdown menu, select Domain Defaults.
  4. On the Mailing Lists card, find Mailing List Max Message Size KB. Type in a number to correspond to the maximum number of Kilobytes for a message that's sent. (E.g., 4000KB roughly equals 4MB.) If you don't want to limit the outgoing message size, type in 0.
  5. Click the Save button.
  6. Once you've modified this setting, you will want to propagate the change to all domains on the server. (If not, you can skip this step and existing domains will remain as they are, but any new domains will use the new setting.)
  7. To do this, click the Propagation button.
  8. A modal window will open, where you can select the setting(s) you want to propagate. 
  9. Once finished making your selection(s), click the Propagate button.
To modify settings for a single domain:
  1. Select the desired domain from the list of domains in the content pane.
  2. The domain's settings will open.
  3. Find the Mailing Lists card.
  4. In the Mailing List Max Message Size field, type the maximum size, in Kilobytes, for all outgoing messages for users on that domain.
  5. Click Save.
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