How do I configure sendmail not to use DNS?
In situations where you’re behind a firewall, or across a dial-up line, there are times when you need to make sure that programs (such as sendmail) do not use the DNS at all. With older releases of version 8 sendmail (8.7 and earlier), you needed to recompile the binary and make sure that “NAMED_BIND” was turned off in src/conf.h. With versions 8.8 and later, you change the service switch file to omit “DNS” and use only NIS, files, and other map types as appropriate. More information about the service switch file can be found under the ServiceSwitchFile option in §5.6 (Options) of the Installation and Operation Guide and all of §4.9 (Name Server Access). And note that you’ll need to forward all your outbound mail to another machine as a “relay” (one that does use DNS, and understands how to properly use MX records, etc…), otherwise you won’t be able to get mail to any site(s) other than the one(s) you configure in your /etc/hosts file (or whatever).
In situations where you’re behind a firewall, or across a dial-up line, there are times when you need to make sure that programs (such as sendmail) do not use the DNS at all. With older releases of version 8 sendmail (8.7 and earlier), you needed to recompile the binary and make sure that “NAMED_BIND” was turned off in src/conf.h. With versions 8.8 and later, you change the service switch file to omit “DNS” and use only NIS, files, and other map types as appropriate. More information about the service switch file can be found under the ServiceSwitchFile option in §5.6 (Options) of the Installation and Operation Guide and all of §4.9 (Name Server Access). And note that you’ll need to forward all your outbound mail to another machine as a “relay” (one that does use DNS, and understands how to properly use MX records, etc…), otherwise you won’t be able to get mail to any site(s) other than the one(s) you configure in your /etc/hosts file (or whatever).
