When synchronizing IMAP folders (probably POP as well, but I don't use that), the progress indicator in the status bar displays an upward arrow.
Even if you know that the arrow is a details button, this is disturbing, as an upward arrow is strongly associated with uploading resp. synchronizing up.
In some circumstances (e.g. after hitting other bugs making you nervous about your data) this is even more disturbing: you know for sure that there is nothing to synchronize upwards, so you're fearing that kmail/Akonadi might do something with the data on your server that it shouldn't do.
Again, knowing doesn't help as our limbic system doesn't care.
It would be expected that the arrow indicates whether currently data is being synchronized up resp. synchronized down. The progress details button should use a different icon. However, plus and minus wouldn't be better, as these are associated with adding resp. deleting items.
The best approach I can come up is a magnifier icon on a snap-in / snap-out button.
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.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.