Hello Railway support / community,

I’m seeing failures sending OTP emails from my app after migrating to the Hobby ($5) plan. This was working reliably under the free plan — the app’s SMTP configuration and credentials were not changed — but now the app fails to connect to the SMTP server and OTP emails are not delivered.

Error SMTP: [Error no 101] Network is unreachable

What I’m doing

• Application: Python/Flask app sending OTPs with smtplib (STARTTLS) to smtp.gmail.com:587 (Gmail SMTP).

• Configuration: same env vars as before (SENDER_EMAIL, SENDER_PASSWORD, SMTP_SERVER=smtp.gmail.com, SMTP_PORT=587) — credentials are valid and use an app password for Gmail.

• Behavior:

  • On the previous free deployment this worked.

  • After upgrading to Hobby ($5), the app still runs, but every OTP send returns the Network is unreachable error from the server logs and the email is not delivered.

  • I can confirm the application code path is reached — it attempts to open an SMTP connection and fails with the network error (so it’s not an authentication failure).

Why I think this is a network/egress issue

• The error is a low-level socket error (Network is unreachable), which usually indicates outbound TCP connections to that host/port are not possible from the runtime environment (blocked egress, routing issue, firewall, or networking misconfiguration), not an SMTP auth error.

• My SMTP settings/credentials were not changed — same config worked previously — so it’s unlikely to be a config bug on my side.

Thanks in advance — I rely on OTP emails for user access and this is blocking logins.

Best regards,
Jefferson