"There is no valid signing certificate ( PGP or S/MIME ) ..." error on Windows

Hello all,

I’m having trouble with using my S/MIME certificate.
I could able to use my cerc on Outlook with GPG4Win plugin.

I can add my certificate successfully, which has .p12 extension.

But when i try to sign mails, i get below error.

I’m looking for solution.

eM Client Version : 7.2.36908.0
OS : Windows 10 x64

any help ?

any help ?

any help ?

any help ?

any help ?

any help ?

any help ?

any help ?

Maybe the certificate/key you imported is not fully compatible with eM Client.

Can you remove it, then create one using eM Client’s own feature and see if you get the same problem.

Thank you for your answer, but i can’t generate S/MIME cert on eM Client, it only generates PGP cert, and i have to use S/MIME cert to mailing with clients.

I’m creating my own cert with OpenSSL as below;
First creating x509 formatted .csr and sign it under Root Ca.
After that, i convert that created cert to .p12 format.

It should work i suppose, because it is the default procedure.

All my keys were brought over from Linux and work just fine. I have one S/MIME that I use regularly for signing, but the others are all either Open PGP or a few PGP generated by eM Client.

Maybe there was something when you created and converted the certificate that makes it incompatible with eM Client.

If you have a Pro License, best bet would be to open a support ticket directly with eM Client. I am sure they will be able to assist you further. If you are just evaluating the application, then unfortunately there is not really any support contact directly with them.

i see, thanks for leading.

Experiencing the exact same issue. Three of my S/MIME keys work fine and were generated on the same machine, app, and format. My most recent key, generated today in the duplicate fashion to the other three , is providing the same error as the OP. Edit: Verified I am fully updated on the client and no change.

Is that also on 7.2.36908? You did not say which version you are using.

Could you clarify your comment, as I don’t recall any recent versions being able to create S/MIME keys.

Hi there, sorry I was unclear. All keys were generated outside of EM Client, (Kleopatra-generated), but only my most recent one for my personal domain won’t function in the same manner as my gmail, outlook, protonmail keys. Anything I else I can provide?

Update: I’ve created a new keypair (RSA:4096) in EM CLient for my email account and I’m still getting the previously stated error message as well. Not sure if that helps. If you have an ftp or Dropbox I can zip up some data if that helps. The account is brand new so there’s nothing crucial about exposing these keys.

Update #2: It just occurred to my that the Free version of EM-Client only supports two addresses and I’ve been trying to use a third. I’m not sure if that is part of the issue but I’m upgrading to Pro to verify.

Am interested to hear what happens after activating the Pro License. Maybe with all three accounts usable, it will make a difference.

Ahmet, you did not say if you were using a Free or Pro License. Is this maybe the same situation?

Update: I’m still in a trial mode at present so it allows more than 2 Inboxes. Whether 100% of functionality is available in Trial is unknown. ( I have purchased licences but wanted to see if this issue could be resolved before I bypass it with $$$). 

I’ve modified system dates/times in an attempt to force the app to exceed the trial alotment, but there’s been no change in the resulting “There is no valid signing certificate” error. I’ve also replicated this error on two other systems.

The evaluation mode of eM Client is fully functional with all the features you will have after activating a Pro License.

As far as I know, the Free License only limits the number of email accounts you can have, as well as some limitation on translations.