Using akonadi 1.12, kmail only stores sent email in akonadi database and not on disk. This happens both in kdepim 4.12.3 and also after upgrading to kdepim 4.13RC1 (marking as major since there is actually data loss here). Feel free to downgrade. Reproducible: Always
Even manually moving any email within kmail to 'sent-mail' folder doesn't really move it physically on disk.
Same here, kubuntu and KDE 4.12.97
as of this morning, it appears that the emails I sent out yesterday survived in my local 'Sent' folder thru multiple reboots. Fixed?
Yes. It seems fixed in akonadi 1.12.1 I will close the bug.