I'd recommend you keep using Heroku, and use a service such as Mailgun for emails. The only change you'd need is to add SMTP parameters for mailgun/whatever in

I'd recommend you keep using Heroku, and use a service such as Mailgun for emails. The only change you'd need is to add SMTP parameters for mailgun/whatever in heroku and django config. If you still want to host your own email server, perhaps setup a Digital Ocean instance and have the smtp credentials on heroku.