Email encrypted - by sender or encrypted mailbox

Distinguishing Encrypted Mailbox from Sender Encryption

If you have activated our automatic encryption through the option encrypted mailbox, you can no longer tell whether a mail was encrypted by the encrypted mailbox or already by the sender, if you use the same public key for both.

However, you may want to know this in more detail.

You can achieve this with a simple trick:

Simply generate a second PGP key that you do not distribute but use exclusively for the encrypted mailbox. In this way, you can clearly identify by the key IDs whether the encryption of this mail was performed by the sender or by the encrypted mailbox.