Outbound Mail Guard protects the server’s reputation by limiting and watching the mail that accounts send out, so one compromised account cannot get the whole server IP blacklisted.
Where
Admin panel → Email → Outbound Mail Guard.
What it does
- Sets sending limits (for example messages per hour) per account/domain.
- Flags or holds unusual outbound volume that looks like a hacked account or a script sending spam.
- Gives the admin a view of who is sending how much, to catch abuse early.
Tune the limits to your real traffic; legitimate bulk senders may need a higher limit, while a default account rarely needs a high one.