A checklist for creating a “mailout” server with DKIM and SPF

Create the DKIM DNS Record:
http://www.dnswatch.info/dkim/create-dns-record

Create the SPF Record:
http://www.spfwizard.net/

Do not forget to add a PTR record at your provider!

Verify the settings: Authentication Checker

Use this command:

mail -r xyz@domainthatshouldbeverified.com -s 'testerl vom roman' check-auth-myname=domain.at@verifier.port25.com<

And some more information if your domain is hosting email at Google:
https://support.google.com/a/answer/178723?hl=en
https://support.google.com/a/answer/174124?hl=en

Update 2018-01-25: Update port25 authentication checker URL

• dns
• email
• exim
• spam