# your ISP's SMTP server name or IP address goes here relayhost = smtprelay.someprovider.com # # this line disables spontaneous PPP connections defer_transports = smtp # # this line disables dns lookups for mail. As you are using a relay you really don't need DNS. If you use this you should use an ip address for $relayhost. disable_dns_lookups = yes 并在拨号脚本中加入: /usr/sbin/sendmail -q,