Fixed timing issue

app/src/main/java/eu/faircode/email/Core.java

@@ -661,11 +661,12 @@ class Core {
         if (msgid == null)
             throw new IllegalArgumentException("Message ID missing");
 
+        long uid = -1;
         if (istore.hasCapability("UIDPLUS")) {
             AppendUID[] uids = ifolder.appendUIDMessages(new Message[]{imessage});
             if (uids != null && uids.length > 0) {
                 Log.i("Appended uid=" + uids[0].uid);
-                return uids[0].uid;
+                uid = uids[0].uid;
             }
         } else
             ifolder.appendMessages(new Message[]{imessage});
@@ -674,9 +675,8 @@ class Core {
         ifolder.close(false);
         ifolder.open(Folder.READ_WRITE);
 
+        if (uid <= 0) {
             Log.i("Searching for appended msgid=" + msgid);
-
-        long uid = -1;
             Message[] messages = ifolder.search(new MessageIDTerm(msgid));
             if (messages != null)
                 for (Message iappended : messages) {
@@ -686,8 +686,9 @@ class Core {
                     if (muid > uid)
                         uid = muid;
                 }
+        }
 
-        if (uid < 0)
+        if (uid <= 0)
             throw new IllegalArgumentException("uid not found");
 
         return uid;