smtptester is a tool to help you troubleshoot SMTP problems quickly and easily without having to resort to telnet.
Install wxPython (preferably version 2.9, although success has been reported for 2.8 on some platforms)
pip install smtptester
This should add an smtptester executable to your $PATH.
Here are some key features of "smtptester":
· Tested on OSX, Linux, and Windows
· Graphical (no more telnet)
· Trace window showing live progress from DNS record look-ups through SMTP session
· Ability to override all DNS and SMTP settings
· Support for SASL and TLS