How to verify that SSL for IMAP/POP3/SMTP works and a proper SSL certificate is in use

Credit Robert Asibekov

IMAP via SSL using port 993

• connect to a mail server usin

openssl s_client -showcerts -connect mail.example.com:993 -servername mail.example.com

• Check output and make sure that a valid certificate is shown:

• Make sure that you received IMAP server response:

  * OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA AUTH=CRAM-MD5 AUTH=PLAIN IDLE ACL ACL2=UNION] Courier-IMAP ready. Copyright 1998-2004 Double Precision, Inc. See COPYING for distribution information.