IMAP fetches are extremely slow most of the time, particularly but not only for imap-ssl.mail.yahoo.com I might even get used to it but what really gets in my way is the fact that the preview pane only gets a refresh when the whole queued jobs have been completed. When one message can't get loaded instantly I might try another one, but that is not working due to the situation I have discribed. Reproducible: Always
I confirm this. The preview pane does not respond to commands (other message selections) before whole IMAP is synced.
Additionally, when one IMAP server is malfunctioning (e.g. not responding), all other IMAP servers are blocked. You can update the list of messages but you cannot view any, KMail tells you to wait (forever). The only workaround is to temporarily disable the offending server.
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
(In reply to Denis Kurz from comment #3) this still exists. Generally, this is the case after a lost network connection (e.g. after the computer went into sleep mode).
Michi uses version 5.3.1 as discussed in another bug, setting to confirmed.