diff --git a/imapserver/append_test.go b/imapserver/append_test.go
index fbde472..95616c4 100644
--- a/imapserver/append_test.go
+++ b/imapserver/append_test.go
@@ -59,6 +59,10 @@ func TestAppend(t *testing.T) {
 	tc2.xuntagged(imapclient.UntaggedExists(2))
 	tc2.xcodeArg(imapclient.CodeAppendUID{UIDValidity: 1, UID: 2})
 
+	tc2.transactf("ok", "append inbox (\\Seen) \" 1-Jan-2022 10:10:00 +0100\" UTF8 ({31+}\r\ncontent-type: text/plain;\n\ntest)")
+	tc2.xuntagged(imapclient.UntaggedExists(3))
+	tc2.xcodeArg(imapclient.CodeAppendUID{UIDValidity: 1, UID: 3})
+
 	// Messages that we cannot parse are marked as application/octet-stream. Perhaps
 	// the imap client knows how to deal with them.
 	tc2.transactf("ok", "uid fetch 2 body")
diff --git a/imapserver/server.go b/imapserver/server.go
index b984208..9e1735c 100644
--- a/imapserver/server.go
+++ b/imapserver/server.go
@@ -2732,7 +2732,7 @@ func (c *conn) cmdAppend(tag, cmd string, p *parser) {
 				Received:      tm,
 				Flags:         storeFlags,
 				Keywords:      keywords,
-				Size:          size,
+				Size:          mw.Size,
 			}
 
 			mb.Add(m.MailboxCounts())