Unable to send mail, the following message appears:
An error occurred sending mail: The mail server sent an incorrect greeting: * OK IMAP4rev1 server ready at 12/05/13 12:52:52.
The submission port 587 also configured as alternative port for IMAP:
# telnet smtp.example.com 587 Trying 203.0.113.2... Connected to smtp.example.com. Escape character is '^]'. * OK IMAP4rev1 server ready at 12/05/13 12:31:59
Disable the alternate port:
MailEnable Management > Servers > localhost > Services and Connectors > IMAP (right click) select properties > Also listen on alternate port