Why won't heroku let users use their own sendgrid accounts?
I installed sendgrid addon to heroku with following command:
heroku addons:create sendgrid:starter
and when i log into my dashboard heroku creates me a starter account. How do i use my own sendgrid account that I already have and tested on my app?
Heroku won't prevent you from using your own sendgrid account. You can set your own config vars to setup the credentials of any account you wish.
For example:
heroku config:set SENDGRID_ID=abcd SENDGRID_TOKEN=efgh
Those two config vars will then be available to your app as environment variables.
Provisioning the add-on will only attach a new sendgrid account to your heroku account, and automatically set the config vars. But nothing prevents you from doing that yourself.