How do I prevent my email from being treated like spam?

The most common cause of email being treated as spam stems from how your webserver is configured to send mail. By default, emails sent with the Transport set to PHP will appear as a user called “nobody@yourdomain.com” or something similar. Most spam filters will look at that and assume that those emails were generated by spam bots and thus the message is dumped without any further consideration.

Other causes include messages which have ALL UPPERCASE letters in their Subject field. Don’t do that. You can usually set the subject line for individual emails in your Zen Cart language files.

1. change your email transport method to “SMTPAUTH” (or “sendmail -f” as a last resort). This will cause the messages to appear as they are coming from “you” instead of as coming from your server’s unsigned PHP.
2. the option ‘Emails must send from known domain?’ should be set to True. This will cause e-mail providers see that it is coming from someplace legitimate and not filter it as spam. And, more specifically, your own webserver will not ignore it because it will now appear as legitimately coming from itself (whom it “knows”), rather than from a 3rd-party.
3. AOL and Hotmail dump emails originating from server/client IP addresses that fail DNS reverse lookup. You should talk to your webhost to ensure that your webserver and hosting account / domain are properly configured with a PTR or DNS reverse lookup. If those words/terms don’t mean anything to you, simply talk to your hosting company about them!
4. Ensure you haven’t damaged your own deliverability by fabricating email addresses but not properly handling them with a catch-all or some other mechanism.
5. Use one of the web based spam checkers that you can find on the Internet. (Search for “spam checker”)