Why the difference in email transit times?

Hi gang: I'm using the class.phpmailer.php code to send email -- it works neat -- very classy (no pun intended). I can send an email from my sperling.com domain and it arrives almost immediately. However, when I use the exact same code (except for the FROM address) from kvyv.com (another domain I own), the email literally takes hours (up to 12) to arrive. Any idea of why there is a difference of email transit times between the two domains? Cheers, tedd PS: Note, my receiving email addresses are handled by gmail.com. _______________ tedd sperling tedd@sperling.com