Thunderbird with cyrus-imapd: Why chose client certificate?

[Jorey Bump]

Goetz Babin-Ebell wrote, at 11/13/2008 03:57 PM:

> If you don't want to do client authentication, why do you set
> tls_ca_file at all ?

Hmm, I do it to suppress these errors:

 TLS server engine: cannot load CA data

Setting tls_ca_file to a properly formatted bundle suppresses the error,
but now i'm wondering if that's a good idea. Will this expose my server
in any way? I don't see how, but the documentation (and error) is very
sparse:

 tls_ca_file: <none>
    File containing one or more Certificate Authority (CA) certificates.

There's no mention of client certificate authentication.