text_combined: mark anderson lssdiscerningcom server virtual web hosting multiple domains distinct ip address server handle incoming email domains mx records point another isp perform outgoing email web sites lets say domain1org ip1 domain2org ip2 postfix maincf pmyhostname whatevermyispnet alias_maps hashetcaliases alias_database hashetcaliases myorigin etcmailname mydestination whatevermyispnet localhostcorenetworksnet localhost relayhost mynetworks 1270008 mailbox_size_limit 0 recipient_delimiter inet_interfaces see mention virtual domains host everything cool cgi domain1org sends email pvosgprdomain1org everything mostly cool also domain2org sometimes email rejected destination messages like 554 554 relaying denied ip name lookup failed ip1 ip1 actual ip address destination doesnt like fact seeing email domain2org sent ip address domain1org question get postfix right thing bind ip2 outgoing email sent domain2org guess might possible set ptr records ip1 list domain1org domain2org domains host seems pretty dubious record ptr record mx record differ domain2org thanks guidance mda tue 05 aug 2008 161503 0800 arrange outgoing email sent correct outgoing ip