OT: TLS with lists.cluenet.de (was: Re: static IPs [was Re: ipv6-ops Digest, Vol 159, Issue 1])

[Bjørn Mork]

FYI: Got a temporary a problem with mail to lists.cluenet.de:

  ----- Transcript of session follows -----
<ipv6-ops at lists.cluenet.de>... Deferred: 403 4.7.0 TLS handshake failed.
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old


Caused by:

bjorn at canardo:~$ openssl s_client -6 -connect mail1.cluenet.de:25 -servername mail1.cluenet.de -starttls smtp -quiet
139725204116608:error:1425F102:SSL routines:ssl_choose_client_version:unsupported protocol:../ssl/statem/statem_lib.c:1929:

WTF? I expected "dh key too small" which has been a bit of an issue
since I updated openssl.  But "unsupported protocol"?  That's not good.

But it's confirmed by e.g.

https://ssl-tools.net/mailservers/lists.cluenet.de

This must be embarrassing?  Time to drop the "clue"....



Bjørn