[Dovecot] error and time out

I can't download my email if the email has one attachment. It goes in time out. This is the log: (how to verbose more information in dovecot.log?) version: fedora core 4 and dovecot 0.99-14-4 Can anyone tell me if this can be the problem to not able to retrieve the email from dovecot?

==> /etc/dovecot.log <== dovecot-auth: Sep 28 17:37:03 Info: Login process 8 disconnected dovecot-auth: Sep 28 17:37:03 Info: Login process 8 connected dovecot-auth: Sep 28 17:37:03 Info: Login process 8 sent handshake: PID 22677 dovecot: Sep 28 17:37:29 Warning: Killed with signal 15 dovecot-auth: Sep 28 17:37:29 Info: Login process 8 disconnected dovecot-auth: Sep 28 17:37:29 Info: Login process 12 disconnected