"openssl s_client" sessions fail identically with 77.43.17.211 and 81.252.237.162.
% openssl s_client -starttls smtp -connect 77.43.17.211:25 ... 250 OK ehlo spike.porcupine.org Nothing happens. % openssl s_client -starttls smtp -connect 77.43.17.211:25 ... 250 OK mail from:<wie...@porcupine.org> Nothing happens. Plaintext greetings from 77.43.17.211 and 81.252.237.162 are identical except for the hostname and time-of-day. I suspect a "patch Tuesday" problem. Wietse 220 ssifsrv01.seronosymposia.org Microsoft ESMTP MAIL Service, Version: 6.0.3790.4675 ready at Thu, 12 Apr 2012 14:15:21 +0200 ehlo spike.porcupine.org 250-ssifsrv01.seronosymposia.org Hello [168.100.189.2] 250-TURN 250-SIZE 250-ETRN 250-PIPELINING 250-DSN 250-ENHANCEDSTATUSCODES 250-8bitmime 250-BINARYMIME 250-CHUNKING 250-VRFY 250-TLS 250-STARTTLS 250-X-EXPS GSSAPI NTLM LOGIN 250-X-EXPS=LOGIN 250-AUTH GSSAPI NTLM LOGIN 250-AUTH=LOGIN 250-X-LINK2STATE 250-XEXCH50 250 OK mail from:<wie...@porcupine.org> 250 2.1.0 wie...@porcupine.org....Sender OK