You know the situation all too well.  Your phone starts ringing way more than usual or a small army begins to assemble by your door…

“My email’s not working.”
“I’m expecting a proposal and it hasn’t come in yet.”
“I can’t send anything to people outside the company.”
“How come my outbox still shows 3 messages.”
“I”m getting send and receive errors.”


ELM can help you avoid these situations with a “simple” monitoring feature. The SMTP Monitor in ELM watches SMTP hosts. This can be accomplished a few different ways.

  • If you are using a Service Agent, the Service Agent will periodically establish an SMTP connection to the server and port specified.
  • If you are using a Virtual Agent or an IP Virtual Agent, the SMTP polling is done by the ELM Server.

If the response is negative or slower than expected, notification options can be triggered. You can also monitor your SMTP server performance by monitoring how quickly a response is returned.

SMTP Monitor 1


Negative or slower-than-expected responses trigger a variety of notification options. Several settings are available for SMTP Monitors.

SMTP Monitor 2


At first glance, the SMTP Monitor appears to be another port monitor. However, behind the scenes, the ELM SMTP Monitor Item uses the extended HELLO (EHLO) command to initiate an SMTP session with the SMTP server. The EHLO command also serves to identify the ELM SMTP Monitor as an SMTP client to the SMTP server. The expected reply from the SMTP server is a multi-line response including “250 OK” as per RFC 2821.

If the ELM SMTP Monitor receives “250 OK” within the QoS timeout, then this is a Success result (ELM Event 5510).

If the ELM SMTP Monitor receives “250 OK” after the QoS timeout has expired, but before 2 QoS time intervals have passed, then this is a Quality of Service Warning result (ELM Event 5511).

If the ELM SMTP Monitor does not receive “250 OK” or receives it after 2 QoS time intervals have passed, then this is a Failed result (ELM Event 5509).

So now instead of your users calling to complain about lost email and pulling you off some important task, you can be notified about the SMTP service not working ahead of time and before the phone starts ringing.

“Yeah, I already know Chuck. It will be back on-line in about 2 minutes. Yeah, I’m really that good.”

We hope that you found this article on Using the SMTP Port Monitor – More Than Just a Port Monitor useful and wish you continued success with ELM.