In the functionality of mail clients, it is possible to specify a completely different mailbox as a sender, which is configured using profiles. For example, this feature allows you to enter the mailbox
firstname.lastname@example.org send letters specifying the sender
email@example.com... The user who received the email will see the sender as
firstname.lastname@example.org. (Information regarding the real sender can be found in the technical headers of the letter).
This feature is convenient for using multiple mailboxes by one person, but it can be dangerous when using corporate mail. To disable the ability to substitute a different mailbox, do the following: