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

ENMA implements the following RFCs and an Internet Draft:

- RFC4406 (Sender ID)
- RFC4407 (PRA)
- RFC4408 (SPF)
- RFC4871 (DKIM)
- draft-ietf-dkim-ssp-09 (DKIM ADSP)
- draft-kucherawy-sender-auth-header-20
(the Authentication-Results: field)

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.