[Enigmail] Enigmail and filters that forward

[Joe Irvine]

I have filters set to forward some emails to another email account. The filters 
work flawlessly if I disable enigmail. When I enable enigmail, the forward fails 
saying to check my mail & news settings. How can I set up enigmail to either:

1 - not try to encrypt the forwarded emails or
2 - cache the passphrase, etc. as necessary to allow it to encrypt an not error.