Enum SenderAuthenticationOutcome

Namespace

MailFathom.Domain.Emails.Authentication

Assembly

MailFathom.Domain.dll

What the receiving mail server established about who sent a message.

public enum SenderAuthenticationOutcome

Fields

Authenticated = 2

The receiving server verified an identity, which is the domain the verdict names.

Failed = 1

The receiving server attempted an identity and it did not hold.

Distinct from NotEstablished because something was actually checked. A message whose DKIM signature did not verify, or whose envelope sender failed its SPF policy, carries a statement that the claimed sender is not the sender — which is strictly more than knowing nothing.

NotEstablished = 0

Nothing was established, which is the answer wherever no trusted statement was available to read.

It is a verdict rather than a missing one, and it is what a deployment whose server publishes no results sees on every message. A trusted header that never arrived, an account with no trusted authority configured, a header naming no method this reads, and a header nothing could parse all reach it: none of them is a statement about the sender, so none of them may read as one.

Remarks

The three values answer one question and are never collapsed into a boolean. A message nobody authenticated and a message whose authentication was attempted and did not hold are different facts about the sender, and both differ again from a message this deployment simply cannot say anything about.