I am using CS-Cart MV and I am using the built-in php mail.
Under "Settings -> Company" I have specified various email ID for different functions, exg: admin@mycompany.com, orders@mycompany.com and contact@mycompany.com.
However, when a customer is notified of an order, status change etc, these emails from CS-cart are being flagged as SPAM (both in gmail and yahoo mail).
- PTR record (Reverse DNS). Some incoming mail servers (such as Google, Yahoo and so forth) will not even consider accepting a message from an IP address which does not identify itself with a PTR record in a reverse DNS zone.
- SPF policy. Adding an SPF record to your DNS zone is the best way to stop spammers from spoofing your domain.
- DKIP signature. If the email is from a trusted domain and is successfully verified through DKIM, the email may have its spam score reduced.
In complex these solutions may help you to prevent your messages to get in spam folder of your recipients.