How to use SMIME in OWA for External Recipeints

Question

Hello,
       I am using a hybrid on premises active directory with office 365 environment with AD synced to office 365 using DIRSYNC. We are trying to achieve being able to send encrypted emails to clients using SMIME in OWA. We have
used certutil to import certificates for some internal users which seems to let you send an encrypted email to them. However when creating a contact in AD for the external user and successfully importing the cert (you can see it in the userCertificate and
userSMIMECertificate attribute in the object)  we are unable to email the recipient with an encrypted email as OWA cannot find the certificate. Also the internal users certificates appear in theirs entries in the GAL however the external contacts
do not have their certificate included.
Could someone advise me how to use OWA to send SMIME encrypted emails to external recipients. You can't add a certificate to a contact in OWA as far as I can see.
Many Thanks
Paul

Answer 1

Hi,
Please refer to the following article :
http://blogs.office.com/2014/02/26/smime-encryption-now-in-office-365/
Using S/MIME in OWA
In OWA, users can choose different options to encrypt the message and/or digitally sign it using S/MIME.
Hope this helps!
Thanks.
Niko Cheng
TechNet Community Support