Forum Academy Marketplace Showcase Pricing Features

Authorize users emails for use within application

I need a way for my users to authorize their existing email within my application. They should be able to send/receive/delete emails through the application on their own gmail/yahoo/outlook. And we need to be able to alert them of responses to their sent messages.

My developers have been having trouble figuring out how to do this. Are there any plugins you can point me to? Any help is appreciated.