Hi, I am on KDE 6, Debian unstable. I set up KMail/akonadi to receive and send mail through my university mail server. Receiving works fine. However, when trying to send an email, I get:
Failed to transport message. Error during SSL handshake:
error:0A000102:SSL routines::unsupported protocol
I cannot find any settings in KMail or KDE to change the SSL protocol used. And I cannot find a way to show the SMTP communication. How can I fix this?
First – Welcome to the KDE Discuss forum.
I must admit – I’m still on KDE Plasma generation 5 and KMail2 but, from what you’re describing, it seems that, with the KDE Plasma generation 6 KMail, it’s no longer possible to change the behaviour of the outgoing KMail accounts – there ain’t no more an “Advanced” tab for the “Connection Settings” and, possibly, it’s no longer possible to “Auto Detect” the behaviour of the SMTP server handling the sent e-Mail.
Please confirm that, for the case of KDE Plasma 6, that, that’s the case.
BTW – you’ll need to check which Port the SMTP server is using for the reception of the sent e-Mail.
To trace the SMTP protocol, you’ll have to install Wireshark – add yourself to the “wireshark” user group – and then, filter to inspect the protocol handshaking.
thanks for the answer! No, that dialog is still there, but when I try to use “Auto Detect”, it goes quite wrong:
I tried both, SSL and STARTTLS, and different ports (analyzed/discovered with nmap), but so far no success. I don’t like to blindly try stuff, I’d rather know what’s going on and then choose the correct option. But the first problem is that I cannot see the protocol. Using wireshark doesn’t really help because it’s all encrypted…
oh! I have to take the last sentence back: it may be encrypted, but wireshark still can show the TLS version. And the result is: KMail is using TLS 1.0 but the mailserver expects at least TLS 1.2.
Sooo. How to make KMail use a newer TLS?
Yes, agreed – the Auto Detect doesn’t always function as expected.
Please check which Port your university’s Mail Server is using.
Then select SSL/TLS.
BTW, I checked what my Plasma 5 KMail is doing when talking to my ISP – no prizes for seeing who I use – 1&1 (United Internet) – Wireshark trace attached – KMail and 1&1 use either TLS v1.2 or, TLS v1.3 …
I actually misinterpreted the Wireshark log the first time. You are right, KMail is using TLS 1.2/1.3. However, my mailserver only supports TLS 1.0! Gee 
I just verified it with sslyze – and indeed, only TLSv1 and SSLv3 are supported. I guess there is not much I can do now since my end is fine and KDE probably won’t support TLSv1 anymore.
