Sorry to make noise.
My 9front version has that option, and I used that option like:
/mail/lib/remotemail
exec /bin/upas/smtp -s -t -d -h hera.eonet.ne.jp -g 192.168.11.1 -u kokamoto%hera.eonet.ne.jp tcp!smtps.eonet.ne.jp!465 $sender $* >[2] /mail/tmp/smtp.err

I got the /mail/lib/smtp.err like:
send ClientHello
	version: 0303
....

recv ServerHello
	version: 0303

....

recv Certificate
	<1751>....
....
	<1105>....
....
recv ServerHelloDone

tls secrets

send HClientKeyExchange
....
send HFinished
b57615488264d5de988f4af3

recv HFinished
4c3f70ee45cef0269479e4ac

Fri Mar 23 09:05:47 JST 2018 connect to tcp!smtps.eonet.ne.jp!465 (smtps.eonet.ne.jp:203.140.81.13) hello:

QUIT
220 mailauthmsa11.mozu.eo.k-opti.ad.jp ESMTP Fri, 23 Mar 2018 09:05:47 +0900

/sys/log/smtp.fail is:
ci5dell Mar 23 09:05:47 delivery  at tcp!smtps.eonet.ne.jp!465 (smtps.eonet.ne.jp:203.140.81.13) hello failed: 

Kenji