The message may be new (though I haven't seen it) but the problem with editing messages in the outbox resulting in the message not being sent is by no means a new one. It is however easily resolved with a macro. Add this macro to the ribbon and use it to resend the messages in the Outbox then res-synch the messages.
Code:
Option Explicit
Sub SendAndReceiveAll()
Dim olNS As NameSpace
Dim olSyncs As SyncObjects
Dim olSync As SyncObject
Dim olItems As Items
Dim olItem As Object
Dim i As Long
Set olNS = Application.GetNamespace("MAPI")
Set olSyncs = olNS.SyncObjects
Set olItems = olNS.GetDefaultFolder(4).Items
For i = olItems.Count To 1 Step -1
Set olItem = olItems(i)
olItem.Send
DoEvents
Next i
For i = 1 To olSyncs.Count
Set olSync = olSyncs.Item(i)
olSync.Start
DoEvents
Next
lbl_Exit:
Set olItems = Nothing
Set olItem = Nothing
Set olNS = Nothing
Set olSyncs = Nothing
Set olSync = Nothing
Exit Sub
End Sub