Invalid certificate error message when replying to digitally signed messsage - OL2007 / Vista

[Jim Carter]

I use OL2003 and digitally sign my outgoing mail. I have heard no complaints
from users with OL2003 and we have verified this is only an issue on OL2007
(and maybe Vista).

The email recipient responds to one of my digitally signed emails and gets
the message "Invalid Certificate. Microsoft Office Outlook cannot sign or
encrypt the message because your certificate is not valid". It then allows
him to deselect "Add a digital signature to the message" in the Security
Properties window.

This recipient normally does not digitally sign his outgoing mail, but it
appears to be a problem only in OL2007. Apparently the message settings are
taking precedence over his local settings and expecting him to reply to a
digitally signed message with a digitally signed response. That's not a good
assumption for OL to make.

Is there a setting that should be changed on the recipient's system to
prevent this from occurring or is OL2007 forcing us to go to digitally
signed mail?

 

[Brian Tillman]

This recipient normally does not digitally sign his outgoing mail,
but it appears to be a problem only in OL2007. Apparently the message
settings are taking precedence over his local settings and expecting
him to reply to a digitally signed message with a digitally signed
response. That's not a good assumption for OL to make.

It's the one OL 2003 makes as well. As far as I can tell, Outlook (both
2003 and 2007) will attempt to sign a reply to a signed message and I don't
believe that's a user-selectable feature.

 

[Jim Carter]

It's the one OL 2003 makes as well. As far as I can tell, Outlook (both
2003 and 2007) will attempt to sign a reply to a signed message and I
don't believe that's a user-selectable feature.

Ah, not necessarily so Brian. We checked this out by having the recipient
switch to his OL'03 machine and he is not forced to apply a digital
signature to my emails when he replies. This is only a "feature" of OL'07 or
maybe Vista.

 

[Brian Tillman]

Ah, not necessarily so Brian. We checked this out by having the
recipient switch to his OL'03 machine and he is not forced to apply a
digital signature to my emails when he replies. This is only a
"feature" of OL'07 or maybe Vista.

When I tried it with OL 2003, replies to signed messages were always signed
by default.