We have setup an email support address which customers will be able to email their support request to.

The E-Mail service is set to check for new messages every 2 minutes and during testing has always found a new message and added it to the database OK.

However, it only sometimes will autorespond to the sender.

If we reply to the email from OnTime, then there isn't a problem, it only is a problem sometimes with the autoreply.

We have checked all our email logs and found that the email message isn't hitting our POP3 server.

We don't have port 25 AV switched on on the server, nor do we have SSL switched on.

Any ideas?