Limit e-mail sending rate (SB-1097)
I would like to limit the number of e-mails a user can send. A "rate limit" could be assigned to users, with a global default value, possibly overrided on individual accounts. This limit could be expressed as a number of messages per time unit (X messages each hour) or a number of recipient per time unit. This option could limit the impact of the identity theft by spammers.