sendmail[]: can't lookup data via name server "dns" or sendmail[]: can't lookup data via name server "nis"

Cause

The following entry in the /etc/nsswitch.conf file, sendmailvars: dns nis files, causes the messages to appear in the console window.

Action

The sendmailvars database can be used only with local files and/or NIS+. If you do not have this database setup, the default sendmailvars entry should look as follows in the /etc/nsswitch.conf file:

sendmailvars: files