Trying to decrypt email in Gmail

For years I have been using Outlook combined with GNU Privacy Assistant to decrypt emails sent from our server. Public key is located on server which is used to send encrypted email to me. All I have to do is from Outlook > Action > decrypt the email.

Now I am planning to abandon Outlook and move to Gmail since its features are going to double my productivity. Everything is great with Gmail except opening those encrypted emails. So I found this well written article on google: http://www.technovisionary.com/howto-se … gp-encrypt
Also learned about Philip Zimmermann a little bit. Got to check out the zfone soon.

Anyway, I followed the instruction and I could not make it work. I have replaced the old public key on the server with the new public key generated by the FireGPG. Is there anything else I am supposed to do?

Although article said Gmail will detect the encrypted email and show button to decrypt, I do not see any of those. So I select all the text from ---BEGIN PGP MESSAGE ---- to the end of ---END PGP MESSAGE--- and right click and FireGPG > decrypt.

Here is error I get
Decryption failed. Unknown error.
gpg: invalid radix64 character 3A skipped
gpg: invalid radix64 character 2E skipped
gpg: invalid radix64 character 2E skipped
gpg: invalid radix64 character 28 skipped
gpg: invalid radix64 character 29 skipped
gpg: CRC error; 1AD133 - 58EC8A
gpg: [don't know]: invalid packet (ctb=55)
[GNUPG:] NODATA 3

Thanks for any help.

Shwe