An article that groups the configuration steps needed to get a domain started with email sending and receiving.
This article makes the assumption that you have already installed a basic SMTP server installation such as PostFix.
email authentication is based:
It's used against spoofing, phishing or impersonation.
Implementation:
Configuring the reverse IP is part of the authentication.
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.
The server does not have a Fully Qualified Domain Name (FQDN) and a PTR record
You may want to change your pointer (PTR type) DNS record and the host name of your server to the same value.
Domain-based Message Authentication, Reporting & Conformance (DMARC) specifies how your domain handles suspicious emails.
Microsoft server (Outlook, etc.) implements a white list policy where you can declare your server: For any problem, see New support request
The IP address of your sender server should not be blacklisted.
If a server shows bad email behavior (such as spam, spoofing, ddos), the server can be blacklisted.
Hosts are often blacklisted with spam filters, including known hosts such as HostGator or Blue Host.
See spam score
Use an email address from the same domain as your website in order to improve the spam score. Example:
When you are done with the configuration of your server and domain, you can validate it. See Email - How to test if your server email configuration was done correctly ?