Nylas integrates with 100% of email, calendar, and contacts providers and we support several authentication types including modern OAuth authentication for Google and Microsoft accounts and secure password authentication for legacy servers.
Furthermore, Nylas supports identity providers (IDP) with single sign on (SSO) capabilities like Okta and OneLogin. If your customers require SSO for their Office365 or GSuite accounts through a 3rd party IDP, as long as you support OAuth authentication for Office365 or GSuite you can authenticate these accounts as you normally would with no additional setup.
Nylas provides two authentication flows to sync email, calendar, and contacts account data: Nylas Hosted Auth and Native Auth.
Nylas Hosted Authentication is the quickest and easiest way to set up user authentication for your app. Simply redirect users to a Nylas login page and we'll handle the rest including auto-detection of third-party providers and managing token exchanges.
Nylas Native Authentication is for developers who want to completely white-label the authentication experience to perfectly match your app. With Nylas Native Auth, your users authenticate directly in your app without ever needing to redirect to the Nylas Auth service. This gives you full control over the flow and look & feel of the login experience, and also allows you to control which kinds of providers your application supports. With Native Auth, you're required to set up developer apps with third-party providers like Google and Microsoft and configure your Nylas application to manage authentication credentials with them.
This is significantly more complicated than hosted authentication, so it's only recommended for developers who absolutely need customization control.