Perfect Email Server Setup - Webmail Tweak Checklist - Avoid Spam

Here is the perfect email setup checklist.

1) rDNS with hostname

2) SPF record

3) DKIM record

4) DMARC record

5) MX record

6) SRV records

6) IP Blocklist

7) IP reputation
https://www.talosintelligence.com/reputation_center/lookup?search=1.1.1.1

8) Mail access secured
SSL activated for mail, webmail, pop, imap, smtp

9) DNSSEC Signed

10) DANE support
TLSA records for mail services

11) SpamAssassin configured

12) Email Content
HTML format, Alt tag for image, No external image by URL, No broken link, Has List-Unsubscribe header

Test mail at https://www.mail-tester.com/

13) Optional: Use IPv4 only, disable IPv6