I use Mutt for gpg-signed email. With previous versions of Ubuntu I could tell Mutt to use gnome-gpg, which would ask for my GPG passphrase with a GUI window and then store it my GNOME keyring for 24 hours or until logout, whichever came first. However gnome-gpg was removed from universe in Ubuntu 11.10. Is there a replacement?
The default keyring manager for GNOME is seahorse:
Seahorse is a front end for GnuPG — the Gnu Privacy Guard program — that integrates to the GNOME desktop. It is a tool for secure communications and data storage. Data encryption and digital signature creation can easily be performed through a GUI and Key Management operations can easily be carried out through an intuitive interface.
man 1 seahorse)
It should be enabled/running by default in Ubuntu and you should have this variable in your environment:
$ echo $GPG_AGENT_INFO /tmp/keyring-XXXXXX/gpg:0:1
/tmp/keyring-XXXXXX/gpg is a socket bound by the program
gnome-keyring-daemon, which is found in the
Unfortunately, I don't have enough information about your system and I cannot tell you how to proceed exactly. However I should have given you enough information to start investigating the problem. If you need more help, please tell me whether you have the package installed, whether the process is running, whether the socket exists and whether the environment variable is set.
I think on 11.10, installing seahorse-plugins should do this for you. And I think in 12.04 and newer versions, the gpg integration will be built-in. I used to have to install seahorse-plugins to make this work in older Ubuntu versions, but on 12.04 I don't have such a package installed, and the GPG integration is working fine for me.
Gnome-GPG won't be avaiable for Ubuntu soon, but you can download the last builds that were made: