Thanks. I've opened a ticket, as the same error is still occuring.
//edit: oops, thought of one more thing and fixed it. I cleared the CA trust for server86, then reaccepted it. Everything's fine now (closed the ticket).
Since Wednesday (1/26), Mozilla Thunderbird has given me the following error when trying to send mail via the TCH mail server:
I have the certificate for server86.totalchoicehosting.com in TBird's Certificate Manager, Authorities tab (set to ID web sites). Not sure what else I can check on my end.