INSTALLED_APPS = [
    # ...
    "anymail",
    # ...
]

ANYMAIL = {
    # (exact settings here depend on your ESP...)
    "MAILGUN_API_KEY": "<your Mailgun key>",
    "MAILGUN_SENDER_DOMAIN": 'mg.example.com',  # your Mailgun domain, if needed
}
EMAIL_BACKEND = "anymail.backends.mailgun.EmailBackend"  # or sendgrid.EmailBackend, or...
DEFAULT_FROM_EMAIL = "you@example.com"  # if you don't already have this in settings