Bug 513674

Summary:	kmail never send email (stuck)
Product:	[Applications] kmailtransport	Reporter:	Benjamin Robin <benjarobin+kde>
Component:	general	Assignee:	kdepim bugs <pim-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	major
Priority:	NOR
Version First Reported In:	git
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Benjamin Robin 2025-12-21 19:57:15 UTC

SUMMARY
Kmail is no longer able to send an email since the update from version 25.08.3-1 to 25.12.0-1.

STEPS TO REPRODUCE
1. Open Kmail
2. Send an email
3. The mail is never sent; it is still in the sender box

OBSERVED RESULT
If I set KSMTP_SESSION_LOG, the log file is created but empty. I added various traces in ksmtp, but the "send" and "receive" functions are never called.

SOFTWARE/OS VERSIONS

Operating System: Arch Linux 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.2-arch2-1 (64-bit)
Graphics Platform: Wayland
Processors: 22 × Intel® Core™ Ultra 7 155H
Memory: 64 Gio of RAM (62.3 Gio usable)
Graphics Processor: Intel® Arc

ADDITIONAL INFORMATION

I do not have time right now to investigate, I have reverted all the KDE packages to the 25.08.3-1 version, and it is working again...

Comment 1 Antonio Rojas 2025-12-21 20:03:31 UTC

The default SMTP port was changed to 465. Try changing it back to 587.

Comment 2 Benjamin Robin 2025-12-21 21:21:24 UTC

Ok, I have should have added more details:
 - The SMTP connection is properly open (checked using Wireshark)
 - I tried using STARTTLS or TLS with appropriate port
 - I checked in more detail with STARTTLS since the beginning is not encrypted, When I try to send an email, the TCP connection is opened, the server replies with "... ESMTP Postcow", but the client never sees this message (I do not see any trace), nor there is any reply from the client (it does not try to authenticate).
 - If I wait a while, the server closes the TCP connection, and in Kmail I have a notification indicating that the server close the connection.
 - If instead I cancel sending the email from kmail, "QUIT" is sent. And this message can be seen in the log.

Comment 3 Benjamin Robin 2025-12-23 08:23:47 UTC

A colleague had the same issue with OpenSuse. And he fixed it by playing with the various configuration options of SMTP (TLS/STARTTLS and port). We found out that I confused/mixup these 2 configuration GUI :
 - Settings -> Configure Kmail ... -> Accounts -> Sending -> Click on line with SMTP type -> Modify -> Advanced (which is for SMTP)
 - Right click on IMAP account -> Account settings -> Advanced -> Section "Connection Settings" (which is for IMAP)

In Wireshark I may have mix-up the IMAP TCP connection with the one for SMTP... 
Really sorry about that... I guess Antonio Rojas was right. I need to update and check.

Comment 4 Benjamin Robin 2025-12-23 08:35:34 UTC

So yeah, it was just as simple as fixing the connection type/port in the GUI.
In my case it was trying to do STARTTLS with port 465 which is not valid.
So I mark this bug as not a bug, but, in practice, a lot of users are going to have this issue. We should handle this more gracefully.