wait until all macros are finished

[Silverfish]

Essentially its as simple as:

If subject contains 'one' Then
(do stuff)
End If

If subject contains 'two' Then
(do stuff)
End If

The issue is, if I get two emails in one send/receive, one email containing 'one' and another containing 'two', then (I would assume) the same macro would try and run twice. Any way to fix this situation?