From: aperson@domain.example
MIME-Version: 1.0
Content-Type: multipart/digest; boundary=BOUNDARY

--BOUNDARY
Content-Type: message/rfc822

Content-Type: text/plain; charset=us-ascii
To: aa@bb.test
From: cc@dd.test
Subject: ee

message 1

--BOUNDARY
Content-Type: message/rfc822

Content-Type: text/plain; charset=us-ascii
To: aa@bb.test
From: cc@dd.test
Subject: ee

message 2

--BOUNDARY--
