My Private Space app sends e-mails to an external SMTP server at port 25. It seems that the app is intermittently having a difficulty in sending e-mails.
Our infrastructure provider applies a throttle on egress network connections to port 25 by default on Private Spaces. To work around this, please:
- Use an alternative port to send e-mails, or
- Contact Heroku Support with the name of the Private Space or the app to have the throttle removed for the Private Space
This throttle doesn't apply Common Runtime apps.