The Episerver Forms module enables submissions to be sent off as webhooks. 

Have a look at this https://world.episerver.com/documentation/developer-guides/forms/implementing-a-customized-actor/webhooks-actor/

You can use webhooks as Marcus's suggestion or implement a custom actor.

Take a look at these

https://world.episerver.com/documentation/developer-guides/forms/implementing-a-customized-actor/

https://github.com/episerver/EPiServer.Forms.Demo/blob/master/Implementation/Actors/InvisibleActor.cs

https://www.dcaric.com/blog/episerver-forms-3-custom-actors

An actor has a property named SubmissionData that contains the submitted data. Inside Run method, use the submission data to do your business.

Thanks Quan Tran,

I've gone through each of the articles previously and they've been very helpful. What they don't explain though is how to pass that SubmissionData to other action methods, say if I want to upse it in a [HttpPost] function. Since the Actor class is not a controller I'm unable to use things like RedirectToAction. Without that method I'm not sure of any other way to move the data to another action.

Edit 08/08/19:

I was able to figure out a solution by triggering a seperate HttpPost function from within the Run method and passing the SubmissionData into it.

Thanks all.