This should be /etc/ssl/cert.pem for us, no?
https://github.com/lefcha/imapfilter/blob/master/src/imapfilter.c#L55
Related ticket here:
https://github.com/lefcha/imapfilter/issues/94
I get that ticket's error on the current port (2.6.1) for one of the
three IMAP domains I filter. Using '-t /etc/ssl/cert.pem' fixes it.
