How can the `to:` and `delivered-to:` fields in an email i received be different?

I received an email and I noticed that the Delivered-To: and To: fields were different. The To: field is not my actual email address, but the Delivered-To: field is. How does this happen?

Delivered-To: [email protected]
To: "[email protected]" <[email protected]>

To add to this - I thought there might be some automatic forwarding setup at my office, but I tested sending something to [email protected] and it didn't come through to me.

Solution 1:

Just like snail mail letters, SMTP email has two different sets of address information: the envelope headers (like the addresses printed on the outside of an envelope) which are used by the SMTP servers to route and deliver the email, and the normal headers, which are part of the mail message and which are only read and interpreted by the user in his mail client/webmail, just like the address attached to a salutation at the start of a physical letter.

Unlike the post office, SMTP usually throws away most of the envelope before it hands the message to the user. I think your Delivered-To: header probably reflects the original RCPT TO: header found in the SMTP envelope.

The To: header is part of the mail message and your address does not need to be there for the message to get delivered correctly. (As long as your address is in the envelope it gets delivered to you.)

You'll find that the case when among others your email gets forwarded or when your address was on the BCC (blind carbon copy) field.

Solution 2:

If its gmail its possible there is a forward or an alias setup. Also I believe if it has either listed for that users mailbox it could report one or the other.

I would suggest verifying Forwarding options are setup correctly after looking to see if either a forward or an alias are setup.

If you send that message to [email protected] and it reported [email protected] I believe that would mean [email protected] is the ACTUAL mailbox label.

Let us know!