On Aug 14, 2009, at 8:53 AM, Jeff Mitchell wrote:
My best guess, after looking at dovecot messages in syslog related to her login, is that Thunderbird is using a secondary imap process to do this copying and this connection times out due to inactivity, so that when she sends mail it has to reestablish itself. For some reason this reestablishment seems to take a very long time, even though her initial login/connection when she opens Thunderbird is very fast.
My guess: Some router/NAT in the middle drops this connection and then when TB tries to send the message the packets get just dropped, instead of being rejected.
