Is Xeams has function like postfix to enable or disable smtputf8?

Like postfix,it can set smtputf8_enable = yes or smtputf8_enable = no at main.cf file.

For some old backend mailserver,maybe it is not support smtputf8

Tommy,

The SMTPUTF8 extension is not available in Xeams. Clients who use non-English characters in their email addresses can use encoding when sending emails. SMTPUTF8 is an optional extension. An SMTP client will switch to encoding addresses when the server does not advertise it.