Josh Good wrote: > On 2017 Feb 11, 19:18, li...@lazygranch.com wrote: >> So technically integrity is assured from server to server, but not between >> clients >> and server. > > That is correct. DKIM is for MTA-to-MTA integrity.
There are no widely used MUA implementations making use of DKIM but it is definitely not technically or standard-wise limited to MTA-to-MTA: https://tools.ietf.org/html/rfc6376#section-2.1 (same text in predecessor RFC 4871) Compared to S/MIME and PGP it provides integrity protection of message headers and body while S/MIME and PGP only sign the message body. Ciao, Michael.
smime.p7s
Description: S/MIME Cryptographic Signature
