After updating to KDE 4.13 RC my IMAP account is unusable in Kmail: after the first mail check it doesn't get any new mail anymore. If I check manually, the progress bar gets stuck at 0%. Trying to send a mail freezes the interface. This worked correctly in the betas. The other two IMAP accounts (Gmail and Hotmail) also work fine. Reproducible: Always
Seems OK in 4.13 final