This is a new installation and most settings are defaults so taking that into consideration, support@ourdomain is a distribution list. My email is the only one as a member. There are 2 support departments currently both using the support@ourdomain. Clients only are allowed to open tickets and 'Pipe replies only' are disabled. Of course this makes no sense since I have no pop3 settings.
Those settings need to be changed but my WHMCS config has no way of checking, receiving, or fetching email in any way at the moment. But this shouldn't matter right? For example if WHMCS creates an invoice and sends the email to the user using phpmail (with reply to support@ourdomain) then that should be it. Customer receives the email and thats that. But it sends support@ourdomain that email error which should have nothing to do with support tickets. What it tells me is that WHMCS is trying to send an email to a customer but the customer has no email address even though they do.
I don't see how email loops would cause this even if we did have some (we don't) since WHMCS isn't fetching or receiving emails. It's just sending out invoice emails and then sending me the error even though the customer receives the invoices.