It seems that this issue is active, i've done some debugging and noticed that postfix answers with: postfix 2.9.6-1~12.04.3 @ Ubuntu 12.04 ```220 2.0.0 Ready to start TLS``` Exchange 2010 @ Windows 2008R2 ```220 2.0.0 SMTP server ready```
In line 234, check_smtp matches against server_expect (-e) which will never succeed, so we could go for "220 2.0.0", defined as a constant. See patch in PR #1378 Addition: maybe the test could be improved, as it only expects for "220" which is returned, but does not test any following string -- Reply to this email on GitHub: https://github.com/monitoring-plugins/monitoring-plugins/issues/1093#issuecomment-146426579
