ENMA is a milter program for the domain authentication technologies.
It authenticates sender's address with SPF, Sender ID, DKIM and DKIM
ADSP, then labels the result onto the Authentication-Results: field.

ENMA implements the following RFCs:

- RFC4406 (Sender ID: Authenticating E-Mail)
- RFC4407 (Purported Responsible Address)
- RFC4408 (Sender Policy Framework)
- RFC4871 (DKIM Signatures, obsoleted by RFC6376)
- RFC5451 (Authentication-Results Header Field)
- RFC5617 (ADSP)
- RFC5672 (RFC 4871 Update, obsoleted by RFC6376)
- RFC6376 (DKIM Signatures)

ENMA is developed by IIJ. IIJ has been using several domain
authentication software, though, all of them appeared unstable. ENMA
is designed and implemented in order to stand large ISP's operation
and is well-tested.

Homepage:
https://enma.sourceforge.net/
