[Dovecot] Dovecot disconnecting while downloading large attachments

Hi,

We're using Dovecot 1.2.15 with Debian Squeeze. The mail server is working properly (we use both POP3 and IMAP) with normal messages, but if we try to download a large message (more than 20mb) using POP3, the server disconnects and our application fails.

It's possible to change this behavior? How can we setup Dovecot so it disconnects after 20 or 30 minutes (I think now is disconnecting after 10 minutes) of "inactivity"?

Regards,

Marc