ftw.mail.mail has now the same ID generation mechanism. 

Registered the INamedFromFile behavior for IBaseDocument and put the Behavior also on ftw.mail.mail. 
I extended an already existing upgrade in opengever.mail, since a new upgrade step does not make sense.

Well now the tricky part :smile: 
Tests are currently failing. because...
I HAVE NO IDEA!!!

If I boot the instance and upload an email by D'n'D everything is fine. The mail gets an ID like "document-12". (The sequence number behavior work fine even in tests.)

If I create the mail with ftw.builder I got the wrong ID. It simply takes the wrong INameFromTitle implementation. But I have no clue why :confused: