mail() function doesn't like Canadian emails?

[wkdown]

Hello all. I'm pulling my hair out over this.
I am trying to get the mail function to send an email to an address ending in .ca (Canadian). The emails are not being sent. I use the EXACT same code and replace the Canadian email with a .com address and it works fine. I send an outside email to the .ca address and it receives it, so I doubt the problem lies there.
I have tried putting the .com and .ca in the TO line:

mail("me@here.com, you@here.ca", $subject, $text, $headers);

I have tried adding it as a CC or BCC:

$headers .= "BCC: you@here.ca\r\n";

I even tried appending the header in the function:

mail("me@here.com", $subject, $text, $headers . "BCC: you@here.ca\r\n");

Does the mail() function not support .ca addresses?

[flann]

try using htmlmimemail5 instead, http://www.phpguru.org/static/htmlMimeMail5.html