A
Anonymous
Guest
Well, the first step is to figure out if the problem is with PHP or with your mail server. So use a regular e-mail client to send a message to one of the problematic hotmail accounts, through the same SMTP server that you have set up with PHP. If the mail arrives, then there's something amiss with PHP, and we can work it out from there. If it doesn't, the trouble is with your mail server, and you should contact your system administrators.