To verify that the Incoming Email address is correct.
Goto <incoming address>/exchange/<user>
So if I am checking my account I should go to https://remote.atriosystems.com/exchange/bcote
If the address does not take you directly to exchange then the Incoming Email router will NOT work. There is no point in trying the email router.
If you get a certificate mismatch then you need to go to the address that the certificate is for. That is why https://atriomain1/exchange/bcote didn't work. The certificate for exchange is for https://remote.atriosystems.com not https://atriomain1.