Mac Sonoma 14.3.1
when sending email to xxx.I.xxx@gmail.com, this is usually returned to me as "mail delivery failed returned to sender" with the highlighted message in the response as xxx.i.xxx@gmail.com.
I am not using a capital L or lower case l (L) in error.
Mike
Advice please
MacBook Pro 13″, macOS 14.3
Because that Username is a not valid username in the domain-name you specified, and the Mail Server that lives there refused to accept mail for those Users.
<<. but that is the email address on received emails. >>
The FROM field when sending an email is filled in manually. it is NOT checked for reasonableness. It need not even be on the same Server. I can easily send emails from AOL with a 'from' Address of Yahoo.
Tthe email system is not case sensitive.
The two Accounts you have mentioned are the SAME email account.
That hasn't explained why they produce a mail delivery failed response.
but that is the email address on received emails
Mac mail address confusing I with i
