I guess that I have read (and used) too much XP driven programming and testing, so I started devising tests after each sysadmin change also. So, here are some tips assorted by services:

Contents: [Dobrica Pavlinušić's random unstructured stuff]
• Dobrica Pavlinušić's random unstructured stuff (smtp) 
• Dobrica Pavlinušić's random unstructured stuff (dns) 

smtp
Test all MX records for domain bobcatsss2008.org by sending e‑mail to test@bobcatsss2008.org
host -t mx bobcatsss2008.org | awk '{ print $4 }' | xargs -i swaks  -t test@bobcatsss2008.org -s {}

dns
Dumps all zones from all name servers.
host -t ns bobcatsss2008.org | awk '{ print $3 }' | xargs -i host -t soa -va bobcatsss2008.org {}