Verifying Sender Rewrite Scheme (SRS) implemented by Blackberry

Question

I have implemented a postfix mail receiving server. On this server I am receiving mails coming from Blackberry too.

Since Blackberry implements Sender Rewrite Scheme (SRS), I want to know how can I validate the authenticity of the SRS present in the incoming mails.

Sample email header that contains Blackberry SRS:

Authentication-Results: dev1.cpgtest.ostinet.net; sender-id=neutral header.from=xxxxxxxxxxx@aol.com; spf=pass smtp.mfrom=SRS0=nRLNv7=UW=aol.com=xxxxxxxxxxx@srs.bis7.eu.blackberry.com

thanks in advance

Ashish Sharma