How to debug Kmail suddenly not sending via SMTP?

JensA · January 5, 2026, 9:02am

I run EndeavourOS on three machines, with KDE and use KMail and related applications.
All machines have similar list of IMAP/SMTP accounts to handle.

Now, suddenly (since yesterday) the two machines I have access to right now refuse to send email. Now I noticed that all identities seem to have lost their folder setup for draft/sent messages. I got an according warning.

Fixed that but still unable to send email. On both machines.

Last update to kmail or akonadi was Dec-19.

How to debug/how to get it working back?

I see some suspicious stuff in journal log but cannot find any details on this

05.01.26 09:36 kmail QObject::connect(KIdentityManagementCore::IdentityActivitiesAbstract, KIdentityManagementCore::IdentityTreeSortProxyModel): invalid nullptr parameter
05.01.26 09:36 kmail QObject::connect(MailTransport::TransportActivitiesAbstract, MailTransport::TransportSortProxyModel): invalid nullptr parameter
05.01.26 09:36 kmail QSaveFile::commit: File (/home/jens/.local/share/kmail2/autosave/{0b3b44e6-8a41-40b3-b12d-bb1d45b620a5}) is not open

JensA · January 5, 2026, 10:09am

Great, on one of the two I can now send again. Just like that.

Meanwhile using Thunderbird did not have any issues to send.

Still want to understand what’s going on here?

Franken14679 · January 6, 2026, 5:24pm

@JensA:

Are you using KWallet to store the information needed to access your e-Mail accounts?
Are the passwords stored in “kdewallet” → “mailtransports” → Passwords → [Transport ID number] visible in the KMail settings for the Accounts → Sending → SMTP objects?

You can decipher which mailtransport ID matches to which KMail Identity by inspecting the file ‘~/.config/emailidentities’.

JensA · January 6, 2026, 6:14pm

hi and thanks for pointing that out. Though not sure how this would help me in this case?

I have again an email sitting in local/outbox (Lokale Ordner/Postausgang) and not getting sent.

Why does it not get sent? Where is the error log for that?

I found Akonadi-Konsole and there a Protocol section. I see a lot of messages but at the end there is a “Offline or busy. See you later.” from akonadi maildispatcher agent?

So what is this supposed to mean? The smtp servers and my PC are not offline. Busy? What is busy? How to un-busy it?

any other ideas?

Just noticed the status on the konsole. Its there at 0% forever

Franken14679 · January 7, 2026, 6:20pm

AFAIK, apart from the systemd Journal, nowhere else.

What I normally do is to use Wireshark to trace the network data stream and check the responses being sent by the remote SMTP agent.

But, before performing a Network Trace, simply, in the KMail Settings, rewrite and save the Password which is stored in the “kdewallet”.