GPGMail: Unusable public key error

santafen's Avatar


31 Mar, 2017 06:13 PM

Whenever I compose an email from a certain address, I get the following error (repeatedly, each time GPGMail tries to save an encrypted version to a Draft)

Unfortunately GPGMail can't handle the error at this point.

Should your problem persist, please contact us at with the following error description:

gpg: C5C27559410A581942BEA7503E0F418F1D0ABB96: skipped: Unusable public key
gpg: -&5: encryption failed: Unusable public key

No error?

macOS           10.12.2     16C67
GPG Suite       2017.1b3    1812    (d43863c)
GPGMail         2.7b3       1215    (d0b5fa0)
GPG Keychain    1.3.3b2     1271    (028a4a2)
GPGServices     1.11        916     (872e77d)
MacGPG2         2.0.30-1b2  887-    (4912d26)
GPGPreferences  2.0.2b3     927     (641418e)
Libmacgpg       0.7         782     (536bf51)
pinentry        0.9.7       4       (b75069d)
  1. Support Staff 1 Posted by Steve on 31 Mar, 2017 09:23 PM

    Steve's Avatar

    Hey santafen,

    welcome to the GPGTools support platform. Sorry you are having problems using GPG Suite.

    First, let's check if your key is ok:

    1. open GPG Keychain
    2. double click your sec/pub key
    3. create a screenshot of the key tab (⇧⌘4 + drag w mouse)
    4. create a screenshot of the subkey tab
    5. attach both screenshots to your discussion by visiting it in your browser

    Should your key have expired, please re-new the expiration date.

    Should your subkey be expired, please create a new subkey.

    1. navigate to the subkey tab
    2. click the "+" button below
    3. confirm with "Generate subkey"

    After that send a signed and encrypted test mail to yourself. Are you able to decrypt and verify the signature successfully?

    In case your key resides on the public key servers, don't forget to upload your updated key, so that the changes are reflected on the key servers.

    Best regards,

    P.S.: You are running an old version of macOS.

    We recommend to update to the latest version of macOS to ensure you have all security relevant fixes from Apple. Here is all information about Apple security updates and here are all security relevant fixes for 10.12.4.

  2. Support Staff 2 Posted by Steve on 07 Aug, 2017 03:56 PM

    Steve's Avatar

    Closing, since no further user feedback was received. Should your problem persist, feel free to re-open this discussion any time.

    All the best, steve

  3. Steve closed this discussion on 07 Aug, 2017 03:56 PM.

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