Hey there! We've found the following might help you get unblocked faster:

• 🧵 Caddy not whitelisting Railways proxy
• 🧵 Support dedicated outbound Static IPs for services
• 🧵 IPV6 only connections won't work due to ip whitelisting
• 🧵 TCP Proxy Template

If you find the answer from one of these, please let us know by solving the thread!

Thanks for the quick response! I reviewed all the linked articles, but none of them solve my specific issue.

The problem is:

- My Django app needs to make HTTPS requests to us.fax.api.sinch.com (Sinch Fax API)

- Railway's network is blocking DNS resolution of this domain

- Error: "Failed to resolve 'us.fax.api.sinch.com' (Errno -2) Name or service not known"

I already tried:

✓ Enabled Static Outbound IPs - didn't fix it

✓ The domain is in Railway's default allowlist (I can access npmjs.com, github.com, etc.)

✓ This is not an IPv6 issue

What I need:

Can you please add us.fax.api.sinch.com to the egress allowlist for my project (casemedix-staff-portal)?

This is a legitimate business API for sending faxes to insurance companies as part of our medical collections workflow.

Thank you!

We do not have a DNS blacklist; that domain simply doesn't have any records.

https://www.nslookup.io/domains/us.fax.api.sinch.com/dns-records/

Hi,

The us. seems to not exist on that domain. Use https://fax.api.sinch.com/.