Send with custom FROM header via external SMTP service

Hello, I am considering using the Mail app but I would like to ensure that my use case is covered before upgrading the OS and then Nextcloud to use it.

My MX records are with Gmail to receive mail, but I SMTP via Amazon SES to send mail because I use a custom email address with each contact. There is a single mailbox in Gmail that functions as a catch-all address. This is easy to configure in Thunderbird on the desktop, especially as Thunderbird allows one to edit the FROM address in the email Compose window.

Can one edit the FROM address in the Compose window with this mail app?

The Mail app allows to create aliases fro each mailbox with different email addresses. I would assume that this is what you’re looking for.