Since yesterday, IMAP connections to imap.1und1.de fail: org.kde.pim.kimap: KIMAP::LoginJob(0x564b0931c4d0) org.kde.pim.kimap: Connecting to IMAP server with no proxy org.kde.pim.kimap: connectToHost "imap.1und1.de" 993 org.kde.pim.kimap: TLS negotiation done, the negotiated protocol is "TLSv1.3" C: A000001 CAPABILITY S: * BYE out-of-sync data before server greeting org.kde.pim.kimap: Received BYE: "out-of-sync data before server greeting " org.kde.pim.kimap: close org.kde.pim.kimap: close org.kde.pim.kimap: Connection to server lost QAbstractSocket::RemoteHostClosedError org.kde.pim.kimap: KIMAP::LoginJob(0x564b0931c4d0) The issue is that LoginJob sends the CAPABILITY command before the server greeting arrived. Apparently this also affects some other mail clients: https://www.batboard.net/thread/15020-bye-out-of-sync-data-before-server-greeting/
A possibly relevant merge request was started @ https://invent.kde.org/pim/kimap/-/merge_requests/11
Git commit dbcedd5aaab1a4e691966d1e37de1a0b413ca605 by Fabian Vogt. Committed on 27/01/2022 at 13:23. Pushed by fvogt into branch 'release/21.12'. Handle pure SSL/TLS negotation in Session instead of LoginJob Previously, LoginJob started the SSL negotiation and immediately sent the CAPABILITY command once it completed, without waiting for the server greeting first. Some servers don't like this any close the connection with * BYE out-of-sync data before server greeting Avoid this by starting the encryption in Session directly, which then starts LoginJob after the server greeting arrived. Adjust LoginJob for this by treating an already encrypted connection like a successful negotation, and avoid handling the encryptionNegotiationResult signal before the job was started. M +7 -5 src/loginjob.cpp M +1 -1 src/session.cpp https://invent.kde.org/pim/kimap/commit/dbcedd5aaab1a4e691966d1e37de1a0b413ca605