Kmail keeps going off-line

For some reason, my IMAP accounts keep going offline and I have to manually put 
them BACK on-line. This is KMail 4.10.5 on KDE 4.10.5 and Fedora 18. I have a 
fully-updated system. 
This happens in less than 24 hours. I typically leave my email up 24/7, but 
I've recently noticed I can read email before going to work and then come back 
and it'll be off-line. This is extremely annoying, especially in my primary 
IMAP account, because I'll go to check another message in the list of emails 
and it'll come up and tell me the account is off-line, but I don't know it 
until I try to change messages!
How can we fix this? Is there a "keep-alive" setting hidden somewhere???
_______________________________________________
KDE PIM users mailing list
Subscription management: https://mail.kde.org/mailman/listinfo/kdepim-users