问题
how to optimize php_mail() w/o sending the email to a spam? everything that my webpage is doing sends the email into spam?how to make it not go to spam??
回答1:
This depends on the spam engine that you have. There is no way you can optimize a PHP function for this. Just try to create the email using correct headers and to be sent from a real email address. If you are doing a newsletter always have a mechanism to unsubscribe, this is a requisite for not entering spam list.
回答2:
Most of the time, it all depends on your domain name or server IP. If you are using a shared hosting server where many other domains were used to spam, the spam filters such as Yahoo, Hotmail or Google may remember it and get your IP blacklisted. If you have already sent lots of mail without the double opt-in system, lots of your recipients may just throw your messages into spam or junk folders and that might get your domain blacklisted too.
Hope it helps a bit.
回答3:
Either you are using a black listed ISP -- check if SPAMHUAS has put them on thier blacklist.
Or your emails look like SPAM to most common spam filters. Either because of the content, (does it look like you are selling Kalashnikovs or drugs that give you a boner) , or, because you have sent thousnads of identical e-mails to the same SMTP server.
Or your e-mail content could be so annoying that many users have hit the "report spam" button.
Incidently even if you are not intending to send lots of e-mails its worth checking out of an ISP is blacklisted before you sign up. That they allow spammers to use there IP is a good indication of thier attitude to thier customers and the public in general.
来源：https://stackoverflow.com/questions/4309690/phpmail-always-go-to-spam