Bug 428536

SUMMARY

I have certain emails, where, when I click to reply to them, and the reply goes all the way through Kmail down into the dispatcher, the email gets thrown out completely resulting in data loss, and no SMTP debug log dump via KSMTP_SESSION_LOG, as far as I am able to assess it so far, despite reporting it's a complete success on all of the frontend desktop notifications and such.

STEPS TO REPRODUCE
1. Click reply to thread which causes issue. Type message. Send message. Nothing happens. Try to check outboxen and sentboxen. Nothing present. Nobody seems to receive it.
2. Dig into akonadictl verbose output and KSMTP_SESSION_LOG. When it happens you will find the error in the title: org.kde.pim.maildispatcher: Item does not have the required attribute Address.
3. When I clicked reply and re-inputted the dest email address it did seem to work, but it is not clear if that is one-off good luck or a reproducible indicator. (This is spamming another user who really isn't up for Linux debugging expeditions...).

OBSERVED RESULT

Email seems to be unrecoverably lost deep under the hood.

EXPECTED RESULT

Email should remain in the outbox with an error on it you can fix and get it to send.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 20.04
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8

ADDITIONAL INFORMATION

I do have some of the KSMTP_SESSION_LOG output of the successful emails, but I cannot get any logs of the failing ones with my current level of expertise, because, as far as I can tell, the only KDEPIM / Akonadi troubleshooting docs which ever existed were deleted from the KDE Wikis, and I do not know enough about Qt to understand how to access any of the MAILDISPATCHER_LOG data which is output all throughout the maildispatcher C++ code. However if somebody can explain how to enable more of this stuff and dump it into some files, I can censor some of the sensitive stuff about the failing emails and add it to the bug report, no problem.