An SRV (service) record specifies information about services that are available on your domain and the location of these services within the domain. There are several fields required when adding an SRV record:
Name: There is a specific naming system for SRV records – underscore followed by the name of the service, followed by a period, an underscore, the protocol and another period.
Host: This should be the system that will receive the service
Priority: Similar to the preference level in an MX record, the lowest number (0) is the highest priority.
Weight: This allows zone administrators to load balance within the zone file.
Port: This should be the port of the services offered.
The above details should be given to you by anyone asking you to add an SRV record to your DNS. Microsoft Office 365 and Google Apps require SRV records to be added in order to use their services with your domain.
