PHPmailer fails on live

Never ran into this problem before in all my years of web development, but oddly enough a site is acting up.

We always use phpmailer to get the job done when sending emails, it is hooked into our backend package that we use开发者_如何学编程 to connect all our clients. All the clients are on the same server and everyone else is working except this site.

Has anyone ever ran into mail not sending live but will send locally and why this happens and how can I fix it. It's being called no different then the rest of them so I'm scratching head trying to figure this out. We do not send via SMTP.

It turns out this was an internal SSL DNS, even though it is the same server it resolves a different DNS so there was some conflict there. So really there was no answer to the question since after all it wouldn't work the same way. Thanks for the comments though.