[Tails-dev] Clawsmail connection problems and Tails

I have been trying for days now to configure Clawsmail on my Tails OS, I
have done everything right but Clawsmail just wouldn't work for me because
of my ISP. It seems like my ISP blocked out most of the ports listed on
openmailbox.org (SMTP /IMAP/POP ports). I really don't know if there is a
way to go around this. I am really interested in setting this up so I can
use PGP to send and receive encrypted messages. Is there a way to open up
these ports so I can finally get Clawsmail to work? I would really
appreciate some help. Thanks