Hi. I use Sylpheed Version 3.2.0beta3 (Build 1122)
GTK+ 2.24.6 / GLib 2.30.0
Operating System: Linux 3.0.0-16-generic (i686)

I set up GnuPG with Thunderbird which was easy but I checked Sylpheed's website and it says you have to compile it to make it work:

GnuPG: Sylpheed can encrypt and sign your messages (also decrypt and verify the signatures of the incoming messages) using GnuPG. GnuPG follows the OpenPGP standard and is compatible with PGP. To enable this feature, you need to install GnuPG and GPGME (interface library to GnuPG). Enable this option with the --enable-gpgme configure switch.
It also says:

2.15 Q15 How do I enable GPG support in Sylpheed?

A. When compiling Sylpheed, make sure you add --enable-gpgme in the ./configure command. When that completes successfully, there is a "privacy" section in the Common preferences.
I'm a newbie and don't understand how to do that. Do I have to do that?

Is there an easy way to sign/encrypt my email in Sylpheed?

Thunderbird is okay but it is slow and bloated, but perhaps that is because I have an old computer. That's why I run Lubuntu (LXDE).

Thanks for any help.
I greatly appreciate it.