Mail Administration Guide

How to Configure NIS and DNS for sendmail

This list includes all the configuration issues that you must resolve before using sendmail when using NIS with DNS as your name service.

mail domain name

If you are setting up NIS as the primary name service, sendmail automatically strips the first component of the NIS domain name and uses the result as mail domain name, for example, ebs.admin.acme.com becomes admin.acme.com.

mailhost host name

When the DNS forwarding feature is turned on, queries that NIS cannot resolve are forwarded to DNS, so there is no need for a mailhost entry in the NIS host map.

full host names

Although NIS does not "understand" full host names, DNS does. This requirement is satisfied when you follow the regular procedure for setting up NIS and DNS.

matching full and short host names

For every host entry in the NIS host table, you must have a corresponding host entry in DNS.

multiple NIS domains in one mail domain

All NIS host maps under a common mail domain should have the same set of host entries. For example, the host map in the ebs.admin.acme.com domain should be the same as the host map in the esg.admin.acme.com. Otherwise, one address might work in one NIS domain but fail in the other NIS domain.