Can S/Mime private key be stored?

Is it possible to store and use an S/Mime private key (email signature) ? Thanks.

Good question, OnlyKey is able to perform signing operations with RSA or ECC keys stored on device. Both PGP and S/Mime perform signing operations but currently we use the GnuPG agent OnlyKey SSH/GPG agent | Docs to do this. I believe GnuPG can support s/mime but I have not tested this it should work.