https://support.google.com/mail/answer/12467704?visit_id=639144648244677793-2853838854&rd=1
About the Gmail Verified Sender Program Pilot - Gmail Help
Update: The Gmail Verified Sender Program Pilot ended on January 31, 2023.
about theverified senderprogram pilotgmailhelp
https://www.plesk.com/kb/support/emails-are-bounced-back-550-the-from-address-does-not-match-a-verified-sender-identity/
Emails are bounced back: 550 The from address does not match a verified Sender Identity - Support...
Symptoms Unable to send email from a mailbox in Plesk the following error is shown: SMTP Error (550): Failed to add recipient "jdoe@example.com" (5.1.1...