Need an option to use mailbox.email as "To" header instead of the alias, when forwarding an email to the mailbox.

[ad-on-is]

Need an option to use mailbox.email as "To" header instead of the alias, when forwarding an email to the mailbox.

[ad-on-is]

Yeah... esample was a typo. sorry for that.

I ditched SL and let my aliases be handled by fastmail.

Anyways.. as far as my knowledge goes, it wouldn't contradict to SL. In fact it's how SL works.

[email protected] sends an email to [email protected]

SL handles that incoming email and redirects it to [email protected] (mailbox). The email headers are now, To: [email protected] and From: [email protected]

When Bob hits reply, Fastmail sets the From header to [email protected] (previous To header) and attempts to reply to Alice to her reverse-alias. But SL will refuse to handle that mail, since it doesn't allow the From header to be one of the aliases, instead it MUST be the mailbox address.

Therefore Bob has to change the From email manually to [email protected], to be able to send the email.

SL and ProtonMail handle this automatically, by using X-SimpleLogin-Envelope-To and X-SimpleLogin-Envelope-From headers respectively. But SL and other mail services don't work together very well.

I hope this makes it more clear.

[springcomp]

Please, can you clarify you use case ?
Did you really want to write esample.com instead of example.com ?

Let me rephrase:

When a mail is sent to alias [email protected], I want fastmail to use my mailbox address [email protected] as the reply-from address.

So you want to hit reply and have SL use your real – hidden – email address instead ?

In my case I want to use the address the mail is sent to, but in this case, when I hit reply in fastmail, it wants to send the mail as from the alias [email protected] instead of from my real, hidden address [email protected].

It appears you definitely want to disclose you real, hidden, email address when replying ?
This contradicts what SL has been designed for, unfortunately.

Nothing, however, prevents you from replying and replacing the reverse-alias address with the real one from the recipient, thereby bypassing SL entirely and sending your mail from Fastmail instead.

Please, feel free to clarify If I did not understand clearly what is your use case.