mail function problems

I use the mail function tons, never had a problem. I am working with a client with a different hosting vendor, they are using PHP 4.2.3, which I guess was a recient upgrade, anyway I was informed by the client that he wasnt getting email submissions from the website, but he was getting other emails, to those same accounts that were from outside the website. Short story long, I took one of the functions that uses the mail function inside of it, and I placed it on my server, and it worked flawlessly, place the same exact code on back on the other site, and nothing. Oh and I dont have access to their error logs. :( What sounds wrong? What sounds bad? Any thoughts? Anything i can look for? thanks, dan __________________________________________________ Do you Yahoo!? New DSL Internet Access from SBC & Yahoo! http://sbc.yahoo.com