It is certainly not an unknown problem, but it should not be insurmountable. The following macro added to a ribbon button can be used to force the messages in the Outbox to be sent:
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
CleanUp:
Set olItems = Nothing
Set olItem = Nothing
Set olNS = Nothing
Set olSyncs = Nothing
Set olSync = Nothing
lbl_Exit:
Exit Sub
End Sub