Sending email using smtp and setting message id

Question

I have a client that sends emails using smtp protocol. The client can be configured on any mail server that supports smtp (for example: gmail, yahoo).

Now, sending mail from the client, I set the "message-id" in the header. Now my question is whether the mail server guarantees that the message identifier set by me in the header will not be reset (or replaced) by the mail server until the mail is actually forwarded.

For example: let my client be set to " [e-mail] ". Now I want to send mail to the address " [e-mail] ". Thus, the client sets the message identifier as " [e-mail] " and sends the mail using smtp.

So now that gmail sends this message to yahoo, it guarantees that my message id will be preserved.

Thanks Kunal

Answer 1

- , , . , , From:. , Message-ID: , , , .

: , , .

Answer 2

. , . , , . smtp , .

( .)