Certificate revocation

Hi there,

I generated an internet certificate to be used for S/MIME for a party outside my company.

I got to know that he wanted to use his existing certificate. So I revoked the one I issued for him.

My question is will he still be able to use this certificate at his end to send/receive encrypted e-mail to our employee (or anyone else) until the certificate expires or will it stop working after the revocation? My understanding is this might work for S/MIME but not for any SSL authentication with the server. Is that true?

Thanks for all your help

Aayz