Rated 3 out of 5 stars

Sent signatures using this addon are marked as invalid. Tested with following receiver clients: Outlook Webmail, GMX Webmail. The "P7S Viewer" says, the given hash is invalid. Same problem using Penango 1.6.1 Also: Sometimes the email was sent encrypted, but only "sign" was selected. Used free certificate of TC TrustCenter GmbH. //EDIT: using Thunderbird, the signature is validated. So it's probably no bug, and only caused by the low publicity of my certificate's CA.

This review is for a previous version of the add-on (0.5.1).