# -Mas -Mai (untrusted caller) need_ipv4 # server PORT_S 220 ESMTP EHLO 250-OK 250-HELP 250 AUTH PLAIN AUTH PLAIN AHVzZXJ4AHNlY3JldA== 235 Authentication successful MAIL FROM: 250 Sender OK RCPT TO: 250 Recipient OK DATA 354 Send data . 250 OK QUIT 250 OK **** exim -odi userx@domain.com . **** server PORT_S 220 ESMTP EHLO 250-OK 250-HELP 250 AUTH PLAIN AUTH PLAIN AHVzZXJ4AHNlY3JldA== 235 Authentication successful MAIL FROM: 250 Sender OK RCPT TO: 250 Recipient OK DATA 354 Send data . 250 OK QUIT 250 OK **** exim -oMas xxx@yyy -oMai zzz -odi userx@domain.com . ****