GPGMail can't decrypt message
If you receive an email that GPGMail can't decrypt, it's possible your secret key is missing from GPG Keychain. Try these suggestions.
- wrong public key used for encryption: The sender might not be using the correct public key to encrypt messages to you: It's possible that multiple keys for your email address exist, so it's best if you send the sender a message with your correct public key attached. See, Email public key.
- Optionally you may want to verify each others public keys, see Verify a key.
revoke old keys: If you have created several keys, consider to revoke old unused keys. See Revoke key.
disable old keys: If you can't revoke old keys, you can instead disable the key. Ask your friends to do the same in their GPG Keychain to avoid future confusion. See, Disable key.
secret key missing from GPG Keychain: You may no longer be in possession of the secret key, needed to decrypt the message. The secret key could have been accidentally deleted. Or it was not transferred to a new computer, you are now using. If you can access the old computer, see Transfer keys to another computer.