TCP/IP-channel-specific options: IGNORE_BAD_CERT (bit-encoded integer)
This SMTP client and SMTP server option controls the MTA's reaction to bad (remote) certificates. Bit 0 (value 1) controls whether a bad client certificate is ignored even when
musttlsserver is set. Bit 1 (value 2) controls whether a bad server certificate is ignored even when
musttlsclient is set. (Note that bad certificates are always allowed in other cases -- e.g., when
maytls* is set.) The default is 3.