how to find webmail location on a private DNS
I purchased a dedicated DNS server and have it configured from a technician who set everything up completely and now the server is hosting my site. Now the tech guy provided all the info. and set up admin email etc. and handled to me but unfortunately that guy recently passed away and i have no idea how to access webmail or find what the incomming mail settings are .... some one advised me to type mail.domain.com or webmail.domain.com in browser and it will direct me to webmail but it didn't work, both primary and secondary DNS are my own ones so have no idea how to access webmail or find incomming server.
Any help will be appreciated.