diff --git a/public/fs/etc/postfix/main.cf.in b/public/fs/etc/postfix/main.cf.in
index 04ca90e..d3ccd93 100644
--- a/public/fs/etc/postfix/main.cf.in
+++ b/public/fs/etc/postfix/main.cf.in
@@ -42,7 +42,7 @@ smtpd_tls_key_file              = /etc/postfix/ssl/certs/culturestrings.org/ssl/
 smtpd_tls_cert_file             = /etc/postfix/ssl/certs/culturestrings.org/ssl/fullchain.pem
 
 smtpd_tls_loglevel              = 3
-smtpd_tls_security_level        = may
+smtpd_tls_security_level        = encrypt
 smtpd_tls_session_cache_timeout = 3600s
 
 smtpd_use_tls                   = yes