we have the latest FortiClient installed on our Win7 computers, with disabled everything except VPN we use for IPSec. Since two days, when we receive a digital signed email using S/MIME, the certificate get' s touched and is not valid anymore. When we disable the FortiClient, it' s working fine again.
We tried is with active and inactive AntiSpam Feature with the same result. Because we can not install the VPN part alone (hopefully that will be proved in future releases) this is a problem for us.
Problem occurred when receiving a signed mail with Outlook 2013 with a GlobalSign and Comodo certificate. A PKI expert analyses the certificate and told us, that the FortiClient check may open the cert file and repacks it and therefore it' s not valid anymore...
If we can not find a quick solution, we have to deinstall it on our user basis and switch to L2TP/IPSec with native operating system connectivity - without FortiToken...
Hope somebody can help.