If I want to send mail by external account.
I mean receiver can see external account in "sent by :".
example I have firstname.lastname@example.org -----> main
email@example.com------> external account
Now I send mail using firstname.lastname@example.org but receiver see email@example.com
in "sent by" ,How I do for receiver see firstname.lastname@example.org in "sent by"?
thank you for answer.