Bug#908649: kmail2: kmail - TLS negotiation was unsuccessful

[Reinhard Karcher]

I suppose, the problem is that openssl minimum protocoll version changed 
to 1.2 and your mail server supports only 1.0.
You could probably restore the old version by changing the last section 
of /etc/sll/openssl.cnf from
[system_default_sect]
MinProtocol = TLSv1.2
CipherString = DEFAULT@SECLEVEL=2
to
[system_default_sect]
MinProtocol = TLSv1.2
CipherString = DEFAULT@SECLEVEL=1
Perhaps you need to change the MinProtocol line to
MinProtocol = TLSv1.0

Reinhard