[exim] sender verify help

ok - thanks in advance for helping me. I'm doing sender verification but
that are some servers out there that don't like <> for a from address. I
think iy's a cisco firewall thing. So - this doesn't quite work for them
- but the postmaster address will work. But on some the callout with
postmaster doesn't work but <> does.

So what I want to do is to let it pass if EITHER one verifies - how do I
do that?

deny    message = REJECTED - The return address you are using\
for this email message <$sender_address> does not seem to be a working 
account.
        !verify = sender/callout=20s,defer_ok

deny    message = REJECTED - The return address you are using\
for this email message <$sender_address> does not seem to be a working 
account.
        !verify = sender/callout=20s,defer_ok,use_postmaster

Also like to suggest a feature to automatically try the postmaster
address if the mail from <> is rejected.