diff --git a/pkg/message/build.go b/pkg/message/build.go
index 71b89fb9..ea1a27e1 100644
--- a/pkg/message/build.go
+++ b/pkg/message/build.go
@@ -491,8 +491,10 @@ func getTextPartHeader(hdr message.Header, body []byte, mimeType rfc822.MIMEType
 
 	hdr.SetContentType(string(mimeType), params)
 
-	// Use quoted-printable for all text/... parts
-	hdr.Set("Content-Transfer-Encoding", "quoted-printable")
+	// Use quoted-printable for all text/... parts UNLESS header is already set
+	if !hdr.Has("Content-Transfer-Encoding") {
+		hdr.Set("Content-Transfer-Encoding", "quoted-printable")
+	}
 
 	return hdr
 }
diff --git a/pkg/message/parser/parser.go b/pkg/message/parser/parser.go
index d74025f5..0f3f05c6 100644
--- a/pkg/message/parser/parser.go
+++ b/pkg/message/parser/parser.go
@@ -109,7 +109,9 @@ func (p *Parser) AttachEmptyTextPartIfNoneExists() bool {
 	h := message.Header{}
 
 	h.Set("Content-Type", "text/plain;charset=utf8")
-	h.Set("Content-Transfer-Encoding", "quoted-printable")
+	if !h.Has("Content-Transfer-Encoding") {
+		h.Set("Content-Transfer-Encoding", "quoted-printable")
+	}
 
 	p.Root().AddChild(&Part{
 		Header: h,