- Heroku Architecture
Databases & Data Management
- Heroku Postgres
- Heroku Enterprise
- Extending Heroku
Outbound port 25 (SMTP) access blocked for Common Runtime dynos
Change effective on 16 June 2021
As part of infrastructure changes that Heroku is rolling out over the coming months, opening outbound connections on port 25 (typically to send emails with the SMTP protocol) will be blocked for Common Runtime dynos.