I am getting following error message while sending emails to some domains.
"TLS is required, but was not offered by host"
In postfix log I am getting following :
86F8C36C0816: to=<firstname.lastname@example.org>, relay=mail.h-email.net[220.127.116.11]:25, delay=5.1, delays=0.38/0.22/4.5/0, dsn=5.7.4, status=bounced (TLS is required, but was not offered by host mail.h-email.net[18.104.22.168])
I found solution on iRedMail forum to set : "-o smtp_tls_security_level=none" in postfix configuration "/etc/postfix/master.cf": but this will practically disable security.
Can You help me please?