Max Message Size

This option specifies the size of the message that will reach the recipient. If you check Max message size in Mail > General > Delivery, the messages larger than the indicated value will be rejected. However, this limit is set on global level and under certain conditions limits set on domain and user level can take precedence.

Global level limit will be applied to all messages from all users in all domains on this server if:

  • in Mail > General > Delivery you check Max message size and set a value

  • in Global Settings > Domains you do not check Override Global limits

In this case any message larger than the size set will be rejected.

Domain and User level limits will be applied if:

  • you check Override global limits in Global Settings > Domains

In this case the limits will be processed in the following order until a non-zero value is found:

  1. User limit set in Domains&Accounts > Management > {domain} > Users > {user}
  2. Domain limit set in Domains&Accounts > Management > {domain}
  3. Global limit set in Mail > General > Delivery

Note: If only zero values are found then the message will reach the recipient.

Example 1

  1. Mail > General > Delivery has Max message size checked and set to 10 MB
  2. Override Global limits is not checked in Global Settings > Domains
  3. Result: any message bigger than 10 MB will be rejected.

Example 2

  1. Mail > General > Delivery has Max message size checked and set to 10 MB (global limit)
  2. Override Global limits is checked in Global Settings > Domains
  3. Global Settings > Domains has also Use domain limits and Use account limits checked
  4. Domain A has Max message size set to 20 MB (domain limit)
  5. User A in Domain A has Max message size set to 50 MB (user limit)
  6. Domain B has Max message size set to zero (domain limit)
  7. User B in Domain B has Max message size set to zero (user limit)
  8. Result:
    • If User A tries to send a 40 MB message, the message will not be rejected, because the user limit in item 5 takes precedence over other limits.
    • If any other user in Domain A tries to send a 40 MB message, it will be rejected as it breaks the domain limit in item 4.
    • If User B tries to send a 40 MB message, it will fail as it breaks the global limit in item 1.