Cannot send email to SOME addresses

I got an email from a customer today. He is unable to remember his password to get into his account.

He tried the "Forgot My Password" function, but it threw back an error.

I tested it with my email address and it worked fine. So I copied his email address into it. I got the error as well.

I am thinking that there is some address validation code in there somewhere, and that is what is kicking up this error.

His email address ends in **@bigpond.net.au **and I am guessing that the net.au portion is what is causing the problem.

Any helpful suggestions would be appreciated (we have customers around the world, so we have to allow for some unusual address configuration I think.

I just tried a test to that same domain without any error message.

Sometimes the mailserver itself prevalidates the email address you're sending to, and will reject the message if it fails validation.

It might be prudent to talk to your hosting company about the issue.

I figured it out....

Turned out that I should have had smtpauth, not smtp (though I had the auth stuff filled in), so it was sending to MY email address cause it is on the same server/domain, but not to anybody elses....

D'oh!