bandwidth shaping

[Alan Bailward]

Hey all, sorry if this has been asked before, but I haven’t really found a good solution.  I have a mac at home and randomly, maybe once a week or once a month, Mail.app will go crazy and use as much bandwidth as I have to pull down mail.  I’m not home so I can’t tell what it’s done or why, and sometimes it stops after an hour, sometimes it goes all night, leaving me with a potentially big bandwidth bill for my colo’d server which hosts my mail (dovecot 1.2.9, postfix 2.7.0 on Ubuntu LTS 10.04).

I’m wondering if there’s a way to restrict bandwidth that’s the “accepted” and proper way with dovecot?  There isn’t anything (AFAICT) built into dovecot, and the alternative seems to be setting up bandwidth shaping with ‘ip’, but that is a pretty horrible nest of ugliness.

Is there a fairly simple setup to set it so imap/pop traffic can only ever use 1mb/s (or some arbitrary number)?  I’m not looking for a one liner, but each time this happens I say “I’m going to figure this out and fix this”, then get lost in ip and shaping queues and give up in frustration until the next time it happens, when I say “I’m *really* going to figure this out this time…”.

Anyone have any pointers? 

TIA

Alan