From 620e316fb463b4525cb8b01d78e2528a22636f19 Mon Sep 17 00:00:00 2001
From: Robert Virkus <robert.virkus@open-xchange.com>
Date: Wed, 15 Apr 2020 14:54:44 +0200
Subject: [PATCH] Always set the MIME-Version header

---
 lib/mail_conventions.dart | 1 +
 lib/message_builder.dart  | 1 +
 2 files changed, 2 insertions(+)

diff --git a/lib/mail_conventions.dart b/lib/mail_conventions.dart
index 04541c09..db18afe6 100644
--- a/lib/mail_conventions.dart
+++ b/lib/mail_conventions.dart
@@ -71,6 +71,7 @@ class MailConventions {
       'Content-Transfer-Encoding';
   static const String headerContentDisposition = 'Content-Disposition';
   static const String headerContentDescription = 'Content-Description';
+  static const String headerMimeVersion = 'MIME-Version';
 //static const String header = '';
 
 }
diff --git a/lib/message_builder.dart b/lib/message_builder.dart
index 7694e63f..52f148b6 100644
--- a/lib/message_builder.dart
+++ b/lib/message_builder.dart
@@ -329,6 +329,7 @@ class MessageBuilder extends PartBuilder {
     if (subject != null) {
       addHeader('Subject', subject, encode: true);
     }
+    addHeader(MailConventions.headerMimeVersion, '1.0');
     if (replyToMessage != null) {
       var originalMessageId = replyToMessage.getHeaderValue('message-id');
       addHeader(MailConventions.headerInReplyTo, originalMessageId);