Set Maximum Email Message Size for Outbound and Inbound messages

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.

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.

Applies to SmarterMail 9.x - 15.x

Incoming Size Limit
At the system level, setting the max message size will reject all incoming messages that exceed the defined value. Follow these steps to set the maximum email size for inbound messages in SmarterMail:

1. Log in as the system administrator.
2. Click the Settings icon.
3. Click Protocol Settings in the navigation pane.
4. Click the SMTP IN tab.
5. In the Max Message Size field, type the maximum size outgoing messages can be.
6. Click Save.

Outgoing Size Limit
At the domain level, setting the max message size will limit the size of email a user can send outbound. Follow these steps to set the maximum attachment size message that a user can send:

1. Click the Domains icon.
2. Select the desired domain in the navigation pane.
3. Click Edit in the content pane toolbar.
4. Click the Limits tab.
5. In the Max Message Size field, type the maximum size outgoing messages can be.
6. Click Save.

Applies to SmarterMail 8.x

Incoming Size Limit
At the system level, setting the max message size will reject all incoming messages that exceed the defined value. Follow these steps to set the maximum email size for inbound messages in SmarterMail:

1. Log in as the system administrator.
2. Click the Settings icon.
3. Click Protocol Settings in the navigation pane.
4. Click the SMTP IN tab.
5. In the Max Message Size field, type the maximum size outgoing messages can be.
6. Click Save.

Outgoing Size Limit
At the domain level, setting the max message size will limit the size of email a user can send outbound. Follow these steps to set the maximum attachment size message that a user can send:

1. Click the Manage icon.
2. Expand the Domains folder in the navigation pane.
3. Click All Domains.
4. Select the desired domain and click Edit in the content pane toolbar.
5. Click the Limits tab.
6. In the Max Message Size field, type the maximum size outgoing messages can be.
7. Click Save.

For more information, please refer to the SmarterMail Online Help.

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