Hijack Detection

Account Hijack Detection

The options on this screen can be used to detect a possibly hijacked MDaemon account and automatically prevent it from sending messages through your server. For example, if a spammer somehow obtained an account's email address and password then this feature could prevent the spammer from using the account to send bulk junk e-mail through your system. You can designate a maximum number of messages that may be sent by an account in a given number of minutes, and optionally cause an account to be disabled if it reaches that limit. There is also a White List that can be used to exempt certain addresses from this restriction.

Account Hijack Detection only applies to local accounts over authenticated sessions, and the Postmaster account is automatically exempt.

Accounts may send no more than [xx] msgs in [xx] minutes

Use this option if you wish to prevent MDaemon accounts from sending more than the specified number of messages in the designated number of minutes. If an account attempts to send more than the allowable number of messages then MDaemon will not drop the connection but it will reject the over-the-limit messages with a 452 error until the time-limit expires. Then it will again accept messages from the account.

Freeze accounts when limit is reached

Check this box if you wish to freeze accounts that attempt to send more than the allowable number of messages. When this happens, the server sends a 552 error, the connection is dropped, and the account is immediately frozen. The frozen account will no longer be able send mail or check its mail, but MDaemon will still accept incoming mail for the account. Finally, when the account is frozen an email is then sent to the postmaster about the account. If the postmaster wishes to re-enable the account that he can simply reply to the message.

White List

Use the White List to designate any addresses that you wish to exempt from Account Hijack Detection. Wildcards are permitted. For example, "newsletters@example.com" would exempt example.com's "newsletters" MDaemon account, while "*@newsletters.example.com" would exempt all MDaemon accounts belonging to the newsletters.example.com domain. The Postmaster account is automatically exempt from Account Hijack Detection.