MailRoute's API makes it possible to tie all sorts of pieces -- like outside applications (like webmail clients), your own billing system, and mailbox lists and preferences -- in with our Control Panel, to automate account management.
For example, if your webmail users write rules to auto Allow or Block, your users can keep doing things just the way they have been doing them all along -- even after joining MailRoute. When they update an Allow/Block entry on your webmail client, it can update in our system as well.
If you have in-house programming talent, you can use our documentation and libraries to implement this quite simply. If you don't, it's something that we can probably do for you.
Our APIs are all documented at https://support.mailroute.net/forums/21682281-API
And we have libraries for all the common web-programming languages (php, python, ruby) at http://github.com/mailroute
If you have questions about what an API is or what MailRoute's API can do to make your life easier, just ask us! firstname.lastname@example.org