All my mails gets marked as SPAM when I send them from the php mail() function in my PHP scripts. Someone at another forum told me that the solution was to use my ISP's (datacenter's in my case) smtp server. So now I've got permission to use their email server and I've also setup my email accounts at their server. I'll also repoint the MX record as soon as this has been solved.

The problem is: I don't know how to make the php mail() function use the new mail server at the datacenter instead of my local sendmail server. Where can I change that in the configuration?

And, Do you think it would help to do this to prevent my mails from getting marked as SPAM? Is there anything else I can do about it?

Best Regards
Oskar R