diff --git a/linux/mail/msmtp.md b/linux/mail/msmtp.md
index 04f645a..88fe96b 100644
--- a/linux/mail/msmtp.md
+++ b/linux/mail/msmtp.md
@@ -13,7 +13,8 @@ edit `/etc/msmtprc`:
 # This allows msmtp to be used like /usr/sbin/sendmail.
 
 defaults
-# Use TLS on port 465
+# Port 587 is preferred, because ISPs often block port 25
+port 587
 tls on
 tls_starttls on
 logfile /var/log/mail.log