Making urn:oasis:names:tc:SAML:2.0:nameid-format:unspecified a supportable identifier format

[Peter Schober]

* Alain O'Dea <alain.odea at gmail.com> [2015-06-12 03:09]:
> Request specified use of an unsupportable identifier format:
> urn:oasis:names:tc:SAML:2.0:nameid-format:unspecified
> 
> If I hack the format I get NameID values I can't use.  I need the email
> address on the SP.

Then use the appropriate NameID format for email addresses.
Clearly you don't want unspecified, as you specifically want the email
address there.
-peter