mail.php error when registering new account

[hfinlay10]

Hi,

I am setting up a site using 1.5.2.1 and all is good, except when someone registers a new account and presses 'Continue' the following error message comes up:

Notice: Error: RCPT TO not accepted from server! in /home/<myserver>/public_html/ocstore/system/library/mail.php on line 614

The registration process actually works, but not surprisingly this error message puts people off and they don't actually know it has been successful. The weird thing is that when 'Continue' is pressed, the browser asks if it should save the password for 'xxxx', the xxxx being what was entered in the postcode field, when it should give the person's name field at that point.

I don't know if it is related by I am using smtp (with authentication) as mail() refused to work.

I have no idea where to start looking for the problem. Any ideas appreciated.

[hfinlay10]

This only happens when I have mail set to 'SMTP', but if I have mail set to 'Mail', then no emails are sent! Argh!

[yakusa47]

I have this kind of error, too. I try :
http://forum.opencart.com/viewtopic.php?f=20&t=57202
http://forum.opencart.com/viewtopic.php?f=20&t=38441
http://forum.opencart.com/viewtopic.php?f=20&t=61793
http://forum.opencart.com/viewtopic.php?f=19&t=29795&start=0

But not solve the problem.