DNS Internet Settings for Small Businesses

I’ve been working with some small businesses, and it makes life a heck of a lot easier for everyone all round if people use sensible DNS names when setting things up.  I’ve looked around and can’t find any suggested best practice, so please see below my suggestions based on all my years experience…  If anyone can point me to any other best practice I’ll be a very happy guy!

• remote.companya.com – This record should be the IP address of the static IP of the main internet connection.  If applicable allow RDP or SSH.
• mail.companya.com – If the company is hosting their own SMTP flow this can be the MX record, it should also be used for OWA and the like.  If the company is sending out email from this address clean onto the internet it will make sense to have the rDNS as mail.companya.com also.