I'm sorry, I obviously accidentially deleted Val's post "Unable to
decrypt" from Tue, 22.10.2013, 23:25 (+2:00). Therefore, I repost his
request:

I've received an email that has nothing in it but a PGP block
starting with the usual -----BEGIN PGP MESSAGE-----, and Enigmail
doesn't seem to recognize it as being encrypted. Clicking the Decrypt
button does nothing, and trying to save the decrypted message just
tells me that the message isn't encrypted at all. For the record, I
shared my key with the person that sent me the mail, and I do have
their key as well.