Email sender refusing to send to unknown ca

[Tim Woodall <debianuser@woodall.me.uk>]

Hi,

Anyone come across delivery failures where the client cert is signed by
an internal ca.

Jun  2 03:45:27 imap202 sm-mta[14736]: STARTTLS=server, error: accept failed=-1, reason=tlsv1 alert unknown ca, SSL_error=1, errno=0, retry=-1, relay=mta140.fwdto.net [195.68.228.140]
Jun  2 03:45:27 imap202 sm-mta[14736]: 3523jQ45014736: mta140.fwdto.net [195.68.228.140] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA-v4

I've not seen this before. It was persistent - tried 75 times over 5
hours before it gave up.

I don't have an easy way to get an email resent from this host. I've
hopefully disabled STARTTLS for it now...