OT: how to block emails sent to too many recipients

[Richard Siddall]

Denis Beauchemin wrote:
> PS: the spam is sent through our webmail (Horde). I cannot stop
> delivering emails from those servers.

Denis,

Do you have Horde's imp/header.php set up to add headers to the outgoing 
emails so you can tell which user account is compromised?

(Presumably it should be possible to configure some outgoing mail 
throttling programs to look at the Horde user in the mail headers and so 
throttle on a user-by-user basis.)

Regards,

	Richard Siddall