SMTP error Your server does not support the encryption type you have specified.

SMTP error Your server does not support the encryption type you have specified.

My client who I configured his Zoho email for has from today only,  getting this error message in Outlool
SMTP error Your server does not support the encryption type you have specified.

The email client has been sending emails normally for many months.
We checked settings and its configred for TLS/587
we change dto SSL/465 and the issue repeats.

We checked his wifes computer, different emaiil account but same settings and the same problem.

I dont know what else I can do to fix this?

domain: rcgd.com.au