[Dovecot] Throttling Logins

[Sean Kamath]

Hi.

Earlier today I was hit with 612 login attempts in 7 minutes.  They  
ramped up slowly, too. :-)

They quickly hit the file descriptor limit.  And then a login server  
spawned and died so quickly that dovecot just died.

My question is, is there a way to throttle the number of login  
connections?  I'm doing it in my firewall now, but it would be nice  
to be able to say something like "max-login-attempts: X" before we  
blacklist the IP (for some configurable time).

yeah, I know V4.2 :-)

By the way, I *really* appreciate all the effort that's gone into  
Dovecot.  Great work, everyone.

Sean