Rated 5 out of 5 stars

*[EDIT]
This plugin exactly does what it's meant to :) My former issues from below have been fixed in three days so five stars not not only for the plugin but also for the good support by GWu!




Hi GWu I just installed this addon in anticipation in TB 16.x because I was looking for something like that for years now!


But unfortunately it does not work right out of the box.* Do I have to activate it somehow? It is listed as active in the Add-Ons. Then I tried the following two from which non of them worked for me:


1. The security settings for my mail account are sing by default and never encrypt. Click "write", added mail address as "To" from which I have the certificate installed (It is listed in the certificate manager under "Your Certificates") when I open "S/MIME > View Security Info" recipient is listed with valid certificate. But when I send the mail I neither get an information from the plugin nor does it activate encryption for this mail.


2. The security settings for my mail account are sing by default and always require encryption. Click "write", added mail address as "To" from which I have no certificate. When I open "S/MIME > View Security Info" recipient is listed with Not found certificate. But when I send the mail I neither get an information from the plugin nor does it deactivate encryption for this mail. Only message I get is that from TB telling me the mail can't be sent because recipient certificate is not available.



What did I do wrong or is there something else I am required to do?



Four Stars because I really like the idea and I really like this to work ;)



[EDIT]

I tried as you suggested and I get the following output in the console:

pref - debug: true

pref - auto_encrypt_ask: true

from: webmaster@tkuhn.de

webmaster@tkuhn.de: null

no certificate for webmaster@tkuhn.de




Which is kind of odd because:

1. I have a valid certificate for webmaster@tkuhn.de listed in Your Certificates

2. I have selected this certificate in the mail account settings I am writing from for signing and encryption (I guess this is the setting the add-on should get the certificate to use from)

3. When I manually activate signing and or encrpyption everything works perfect



Any other Idea? If you need more information feel free to contact me using the email address given above, since this here is a little bi unfitting for support, but I could not find any other way on this site to contact you.

This review is for a previous version of the add-on (0.1). 

You don't have to activate it explicitly, if it's installed, it's active.
Change the default security/encryption setting in your account settings from "Required" to "Never (do not use encryption)" to benefit from the add-on.

Hard to tell what's the issue in your case, maybe TB doesn't find either your own and/or all of the recipients' certificates (the email addresses have to match exactly, obviously).

You can enable debug message for the plugin: Tools -> Options -> Advanced -> General -> Config Editor: set "extensions.encryptifpossible.debug" to true.

Then open Tools -> Error Console , click "Clear" or scroll to bottom.

Compose a new message, add a recipient of which you are sure you have a certificate and save it as draft (Ctrl-S), now the add-on should ask if you'd like to activate encryption.

If not, check the Error Console:

If certificates are found, you can see messages like "alice@bob.com: [xpconnect wrapped nsIX509Cert]", for the sender as well as for all of the recipients.

If for some of the recipients the certificate is not found, there is a message like "alice@bob.com: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIX509CertDB.findCertByEmailAddress]" ... data: no].

Certificates must be found for the sender and for _all_ of the recipients, otherwise encryption will (and can) not be activated.

And thanks for giving 4 stars nevertheless :)