Access Control for POP3 / IMAP

[Martin Schwartz]

Hello,

it seems some guy wants to hijack POP/IMAP accounts from time to time;
trying out passwords by brute force. I'm not sure about the best way to
handle this.

- do you know of a (cyrus or non cyrus) way to block or slow down the
access for an IP / username after n insuccessful login attempts? 

- is there a way to implement access policies for POP / IMAP access?
(like POP polls only each n minutes, or bandwidth control?)

Thanks a lot

Martin