I have a PRTG installation on the Internet. I want to check that mailflow is working correctly into and out of my internal exchange system. However, I don't expose any pop3 or imap mailboxes to the internet, so my PRTG installation can't check for email arrival using the standard SMTP/POP3 round trip check.
I would like to:
- a) have PRTG validate my SMTP gateway is up by sending it an smtp message.
- b) have that SMTP message relayed to my internal mailserver
- c) have the internal mailserver redirect the email to a pop3 mailbox located on the internet
- d) use PRTG to check for the arrival of that return message and alert if it either doesn't arrive within a specified time, or takes too long to arrive.