Possible Duplicate:
sending mail with php & escaping hotmails junk folder
I have been using php mail(); function to send e-mails for registration messages. They keep up ending in hotmail's junk folder. I have SPF set-up, please give my suggestions how to fix this issue? Shall I switch to smtp?
You can never predict what rules will be used to identify spam at large providers like Hotmail, Gmail, etc. If you could, then spammers could too. And that would be bad.
Without more details, we can't see likely problems that would affect your mail. Provide some example code.
Try analysing your messages with SpamAssassin, which you can probably install and run on just about any linux or unix server.
Daniel's link (sending mail with php & escaping hotmails junk folder) is going to be the most useful to you I think. We've been battling spam scores for years and had some decent success simply by following the rules, which you may find in the top answer for that link. In the end, we found it a lot easier to use a third party system like mail chimp to send mailers. Let them take the heat for your mail blasts.
Without providing a huge chunk of code that uselessly reinvents the wheel -
Make sure you have ALL proper headers in place.
Make sure you have an unsubscribe link
Try not to have an unreasonable image to text ratio. Like all image html emails will almost positively be spam to hotmail.
Research hotmail's spam guides and adhere to them
Everything else has been said over and over again.
Please keep in mind, I am not suggesting you use a third party system since that is not what you asked for in your question. I am simply telling you that the firm I work for has battled spam filters for years and though we have large success by following the rules, we have found it a lot easier to just let some other system handle the pain for us - and yes, you still need to follow the rules even if it is not your server. It is cheaper in the long run.
I would up daniel's answer if he turned his comment into a question.
