If your email server used to send email isn't configured properly (Mailgun by default), attempting to send an email will cause an Internal Server Error. By default, ``django-allauth`` is setup to `have emails verifications mandatory`_, which means it'll send a verification email when an unverified user tries to log-in or when someone tries to sign-up. This may happen just after you've setup your Mailgun account, which is running in a sandbox subdomain by default. Either add your email to the list of authorized recipients or verify your domain. .. _have emails verifications mandatory: https://django-allauth.readthedocs.io/en/latest/configuration.html?highlight=ACCOUNT_EMAIL_VERIFICATION