HEY... An MTA server rejected my emails with error 550!

If your emails to a have been rejected with an error message similar to the one below, then it's time to get your email authenticated

the mta server of gmail.com - - gmail-smtp-in.1.google.com(74.125.204.26) reply:550

5.7.26 This mail is unauthenticated, which poses a security risk to the sender and Gmail users. and has been blocked. The sender must authenticate with at least one of SPF or DKIM. For this message, DKIM checks did not pass and SPF check for [example.com] did not pass with ip: [127.0.0.1]. The sender should visit https://support.google.com mail/answer 81126#authentication for instructions on setting up authentication. h6-20020a6540460000006004850715f99si19653637pep. 259 - gsmtp at 2023-03-24 17:36:19

Things are ramping up quickly, so time to get your DMARC house in order... for example:

• ​Microsoft will be rejecting emails that fail DMARC (DKIM/SFP) starting in April 2023

• Google announced it would begin rejecting the same emails to consumer accounts starting in November 2022

Time to get your DMARC house in order 

• Priority #1 - Get DKIM signing up and running

• Priority #2 - Get a DMARC policy and record in place for monitoring your authentication results

• Priority #3 - Get an SPF policy and record