Sender and receiver model
When a mailbox is created, a user is allowed to send mail from and receive mail for his own mailbox address.
Mailbox firstname.lastname@example.org is created. example.org is a primary domain. Note: a mailbox cannot be created in an alias domain. email@example.com is only known as firstname.lastname@example.org. email@example.com is allowed to send as firstname.lastname@example.org.
We can add an alias domain for example.org:
Alias domain alias.com is added and assigned to primary domain example.org. email@example.com is now known as firstname.lastname@example.org and email@example.com. firstname.lastname@example.org is now allowed to send as email@example.com and firstname.lastname@example.org.
We can add aliases for a mailbox to receive mail for and to send from this new address.
It is important to know, that you are not able to receive mail for
email@example.com. You would need to create this particular alias.
firstname.lastname@example.org is assigned the alias email@example.com firstname.lastname@example.org is now known as email@example.com, firstname.lastname@example.org, email@example.com firstname.lastname@example.org is NOT known as email@example.com.
Administrators and domain administrators can edit mailboxes to allow specific users to send as other mailbox users ("delegate" them).
You can choose between mailbox users or completely disable the sender check for domains.
SOGo "mail from" addresses¶
Mailbox users can, obviously, select their own mailbox address, as well as all alias addresses and aliases that exist through alias domains.
If you want to select another existing mailbox user as your "mail from" address, this user has to delegate you access through SOGo (see SOGo documentation). Moreover a mailcow (domain) administrator needs to grant you access as described above.