FAILURE encrypt 53

Matthias's Avatar


10 Oct, 2018 01:17 PM

I'm using GPG with Mailmate on MacOS 10.12 and I get with one recipient the following error:
While trying to send an encrypted message and get the following error:
INV_RECP 0 [email blocked]
FAILURE encrypt 53

The key is valid, but I can't encrypt, what to do?

Please note, with AppleMail I just get the error, Mail can't be encrypted.


  1. Support Staff 1 Posted by Steve on 18 Oct, 2018 10:24 AM

    Steve's Avatar

    Hi Matthias,

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

    Please excuse the late reply, we are deeply sorry for not responding earlier. The amount of feedback we received in regards to the GPG Suite 2018.4 release was overwhelming - both positive and negative. We are doing our best to catch up as fast as we can.

    We do not develop Mailmate nor the plugin for that mail client.

    Regarding and GPG Mail, could you send a screenshot of the error message you are seeing there?


  2. 2 Posted by Matthias Schmid... on 30 Oct, 2018 02:27 PM

    Matthias Schmidt's Avatar

    Hi Steve,

    Thank you for your answer. imho this is not an issue of the MailPlugin
    or the implementation of MailMate, it has something to do with GPG
    I`d just like to understand what’s the meaning of error 53 (I hate
    magic numbers) as I couldn’t find any answers anywhere and it seams no
    one knows, what this error means.

    Thanks again

  3. Support Staff 3 Posted by Steve on 31 Oct, 2018 04:53 PM

    Steve's Avatar

    It seems your OpenPGP Key and or Subkey may have expired. This KB-article explains how to extend the expiry date of your Key and Subkey in case it will soon expire or has already expired.

    Best regards,

  4. Steve closed this discussion on 18 Sep, 2019 03:28 PM.

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