Date: Tue, 31 Aug 2018 16:33:00 +0200
From: From <from@example.com>
To: To <to@example.com>
Subject: Bug 1487421 - BASE64 MIME body and attachment with empty lines in between
MIME-Version: 1.0
Message-ID: <1dcZe4@example.com>
Content-Type: multipart/mixed;
 boundary="------------DA562B250842CC7332F16476"

This is a multi-part message in MIME format.
--------------DA562B250842CC7332F16476
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: base64

YWJj

ZG

V

mZ2hpamtsbW

5vcHFyc3R1dnd4

eXo=

--------------DA562B250842CC7332F16476
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="test.txt"

YWJj

ZG

V

mZ2hpamtsbW

5vcHFyc3R1dnd4

eXo=

--------------DA562B250842CC7332F16476--