When you receive an email, and takes many pictures attached, or few, but the file size is large, the session expires.
This is happening to me from 0.3 version or earlier to 0.7.2, which is running now.
The session expires immediately
Anyone knows some these?
This is fixed in 0.8. The issue is caused most likely by IMAP server unable to handle many parallel connections. In such case earlier versions of Roundcube destroy the session.