microsoft graph - What are the ways to handle authentication for outlook mail api other than using owin middleware? -

i have followed following guide implement oauth outlook mail api.

https://docs.microsoft.com/en-us/outlook/rest/dotnet-tutorial

it uses microsoft authentication library (msal) in combination owin middle-ware authenticate users.

i separate authentication done after main authentication local db.. (seperate module outlook).. authenticated user can opt use or not use outlook features in app.

would there easy way achieve other manually (using http calls) doing authentication?

you can easily. don't need owin use msal. example, login url using getauthorizationrequesturlasync confidentialclientapplication class , use generate login button or link. you'd need implement redirect in app exchange auth code token.