After completing part 1 and part 2, we have a working Postfix SMTP server and Dovecot IMAP server. We can send and receive email using a desktop email client. Although I have created correct MX, A and PTR record, my emails were flagged as spam by Gmail and Outlook mail. So in this part, we … Continue reading Part 4: Set Up SPF and DKIM with Postfix on CentOS 8/RHEL 8 Mail Server