Konfigurasi Email Server Dengan SPF Dan DKIM Di Aplikasi Postfix Pada CentOS 7
Setelah kita melakukan instalasi email server, cek skor email server di website Mail Tester. Salah satu contoh hasil pengecekan website tersebut sebagai berikut. Content: [Text] [HTML] [Source] SpamAssassin: [Score] The famous spam filter SpamAssassin. A score below -5 is considered spam. Authentication: We check if the server you are sending from is authenticated [SPF] Sender Policy Framework (SPF) is an email validation system designed to prevent email spam by detecting email spoofing, a common vulnerability, by verifying sender IP addresses. [Sender ID] Sender ID is like SPF, but it checks the FROM address, not the bounce address. [DKIM] DomainKeys Identified Mail (DKIM) is a method for associating a domain name to an email message, thereby allowing a person, role, or organization to claim some responsibility for the message. [DMARC record] A DMARC policy allows a sender to indicate that their emails are protected by SPF and/or DKIM, and give instruction if neither of those authentication methods passes. Please be sure you have a DKIM and SPF set before using DMARC. [PTR record] 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. [A record] We check if there is a mail server (A Record) behind your hostname. Errors: Checks whether your message is well formatted or not. [Image alternate tag] alt attributes provide a textual alternative to your images. It is a useful fallback for people suffering from sight problems and for cases where your images cannot be displayed. [HTML elements] Checks whether your message contains dangerous html elements such as javascript, iframes, embed content or applet. [URL shortener] Checks whether your message uses URL shortener systems. [List-Unsubscribe header] The List-Unsubscribe header is required if you send mass emails, it enables the user to easily unsubscribe from your mailing list. [Blacklist] Matches your server IP address against 22 of the most common ipv4 blacklists. Untuk meningkatkan skor, kita bisa memperbaiki konfigurasi email server dengan SPF dan DKIM ...