I tried to see if there is any sendmail mailing list but all they had was an announce list. if yu know any other please let me know. Therefore I am posting my question here. I am trying to set up a smart host for sendmail (sending all mail through our mail server smtp engine). The internal Ip of the mail server is 10.0.0.35 Here is what I added to sendmail.mc file: define(`SMART_HOST',`10.0.0.35') MASQUERADE_AS('intellsystems.com')dnl FEATURE(`allmasquerade')dnl FEATURE(`masquerade_envelope')dnl and then I used m4 macro to compile sendmail.cf and restarted sendmail. When I try to send an email it bounces back: here is what I get when I send an email to this address: -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list