While sending email from webmail, I was getting the below error :
SMTP Error (550): Failed to add recipient “firstname.lastname@example.org” (Verification failed for <email@example.com>
The mail server could not deliver mail to firstname.lastname@example.org. The account or domain may not exist, they may be blacklisted, or missing the proper dns entries.Sender verify failed).
1. Check if the MX record for the domain “xyz.net” is valid or not.
2. If MX record is pointing to same server (local) then change Email Routing to : Local Mail Exchanger.
3. If MX record is pointing external server (remote) then change Email Routing to : Automatically Detect Configuration