This article explains how to enable and use the Hornetsecurity signature for outgoing emails, and how to identify any signed emails.


In order to use outgoing signatures, the encryption module from Hornetsecurity must have been purchased and enabled. In addition, the email sender must have valid S/MIME certificate stored within the system.

Outgoing signature

As a SecureGateway, Hornetsecurity manages any signatures directly. For as long as you are using a valid S/MIME certificate in combination with the Hornetsecurity encryption module, any emails of the certificate owner will be signed automatically.

You can disable this behavior by:

1. From within the Control Panel deactivate the option “Signature” from “Management > Email > Encryption > Certificates

2. Add “NOSIGN” as a keyword anywhere within the subject of the email not to be signed.

Incoming signature

Whether or not an incoming email has been signed, can be seen directly through the email client that’s being used. The exact position of that option depends on the distributor of the software, but any signed email will contain a .p7m-file as an attachment, which will contain the signature. For further information on how to identify the signature from within the client, please contact your software distributor.

Control Panel

No matter what direction, you can see the used signature from within the Control Panel. To do so, perform these steps:

1. Log into the Control Panel

2. Locate the appropriate email from the Workspace and open “Infos

3. From the tab “Details” locate the line “Reasons”

If signed properly, you will find „crypt=smime/crypt“ from the reason field.