Hello, Some of my email notifications (sent from [email protected]) from self-hosted Invoice Ninja billing system go to my client's SPAM folder. I ran a SPAM test on https://www.mail-tester.com/ Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address. Some companies such as AOL will reject any message sent from a server without rDNS, so you must ensure that you have one. You cannot associate more than one domain name with a single IP address. Your IP address 18.104.22.168 is associated with the domain mydomain.com. Nevertheless your message appears to be sent from server.mydomain.com. You may want to change the host name of your server to mydomain.com. Here are the tested values for this check: IP: 22.214.171.124 HELO: server.mydomain.com rDNS: mydomain.com Anyone know if rDNS is an issue with emails ending up in SPAM/JUNK folder. Thanks in advance!