Good Question. Thats the way it works for me too. Also, a lot of mail sent via PHP from my plesk machine gets blocked at my mail server because it cliams to be infected with a virus. Here is the message in th avirus log : File(s) are INFECTED [[Outlook 'CR' Vulnerability]: 0] )
I'll be watching this thread for a solution.I don't often see things solved here though. A lot of dead threads.