Mail Connection Doctor is lying

Have been having problems sending messages through a SMTP server, others are ok but this one;

The other servers I tried greets with EHLO, this one old fashioned HELO.

Obviously from the log below, the connection and handshaking completers, even the initial HELO is being sent.

But it just sends QUIT after receiving the 250 response (ok), and lies to me that it could not connect.

I tried this with unencrypted SMTP as well, the same problem.

(SMTP works on the iPad and iPhone with exactly the same settings to the same server)

This has been going on for a while now.

Doesn't Apple have enginners that werent born when the ancient, and simple, SMTP protocol was introduced.

Do you even test your software against Sendmail (8.14.5/8.14.4, or others)?

A junior software developer implements a SMTP cleint in a few days.

OS X 10.8.5, Mail 6.6 (1510)

Gosh.

Connection Doctor says;

INITIATING CONNECTION Sep 28 14:43:02.146 -- host:mail.server.com -- port:465 -- socket:0x0 -- thread:0x7fef443293a0

CONNECTED Sep 28 14:43:02.821 [kCFStreamSocketSecurityLevelTLSv1SSLv3] -- host:mail.server.com -- port:465 -- socket:0x7fef43e71fb0 -- thread:0x7fef443293a0

READ Sep 28 14:43:04.608 [kCFStreamSocketSecurityLevelTLSv1SSLv3] -- host:mail.server.com -- port:465 -- socket:0x7fef43e71fb0 -- thread:0x7fef443293a0

220 mail.server.com ESMTP Sendmail 8.14.5/8.14.4; Sat, 28 Sep 2013 14:43:03 +0200

WROTE Sep 28 14:43:04.660 [kCFStreamSocketSecurityLevelTLSv1SSLv3] -- host:mail.server.com -- port:465 -- socket:0x7fef43e71fb0 -- thread:0x7fef443293a0

HELO [client-ip]

READ Sep 28 14:43:04.738 [kCFStreamSocketSecurityLevelTLSv1SSLv3] -- host:mail.server.com -- port:465 -- socket:0x7fef43e71fb0 -- thread:0x7fef443293a0

250 mail.server.com Hello client-reverse-ns-lookup [client-ip], pleased to meet you

WROTE Sep 28 14:43:04.793 [kCFStreamSocketSecurityLevelTLSv1SSLv3] -- host:mail.server.com -- port:465 -- socket:0x7fef43e71fb0 -- thread:0x7fef443293a0

QUIT