How to integrate GPG with alpine

Very easy! (Well, kinda like a magic trick... easy once you've seen it done...)

In Alpine, go to '(S)ettings', then 'Collection (L)ists', then (A)dd new, fill in the fields:

Nickname: MyGmail
Server: imap.gmail.com/ssl/NoValidate-Cert/user=youremail@gmail.com
Path:
View:

Of course, Nickname is your choice, Server needs your proper email address, leave Path & View empty, there are specialized uses for them, I haven't needed them.

CTRL-X to save

From the main menu, going to 'Folder (L)ist', then selecting your new collection, should cause Alpine to prompt you for your password. Entering that, you should see your gmail folder (label?!) structure. For gmail's purposes, 'folder' and 'label' are identical.

You MAY need to start Alpine with the '-passfile=xxxx' command line option to cause alpine to remember your passwords rather than typing it in each startup of Alpine, but I forget if you need it all the time or just the once to enable it. Try setting up the "collectionlist" first, see what happens, it's been so long since I've started from scratch with pine/alpine/realpine.

You may add as many "CollectionLists" as you like, I've got several other imap accounts listed, you can adjust the order to put more frequently used ones up top or whatever.

I seriously recommend walking through the entire list of 'config' options and using the '?' help function to learn what everything does.

Hope it helps.

Yes, both GnuPG and the commercial PGP.com are implementations of the same OpenPGP standard; in fact, GnuPG was specifically designed to be PGP-compatible.

The only differences you might encounter are:

• Different supported algorithms. For example, GnuPG supports the Camellia encryption algorithm, while PGP.com does not.

  This is almost never a problem, though, as every PGP certificate ("PGP key") lists all algorithms that the owner's software supports (or more precisely those which the owner prefers to be used), so a message's sender can always pick a supported one.

• Various quirks and differences in really old versions of PGP (especially the original releases from before OpenPGP was standartized). However, both GnuPG and PGP.com can easily read (if not always write) messages in the old formats.

tl;dr: Yes, they are compatible.