Make sure the email is correct, Try check another folder, or open the "All Mail" folder

A few things worth checking/trying since Railway says the invite was sent but it's not arriving:

1. Spam/Promotions/All Mail folders Railway invite emails sometimes get filtered, especially on corporate email providers with strict spam rules.
2. Check the exact email address re-open the invite dialog and verify there's no typo, extra space, or autocomplete substitution in the email field before resending.
3. Email provider blocking some providers (particularly corporate Google Workspace or Microsoft 365 tenants with strict security policies) silently drop transactional emails from unfamiliar senders. If the invitee is on a work email, try inviting their personal email (Gmail, etc.) as a test to isolate whether it's provider-side.
4. Check spam/allow-list on the recipient's side for Railway's sending domain if you have access to their mail admin console, whitelisting Railway's sending domain can help.
5. Try resending after a few minutes occasionally there's a delay in delivery rather than a hard failure.

If none of that works, this is likely something on Railway's transactional email delivery side (not your account config), so it'd be worth flagging to Railway support directly with:

• The exact invitee email
• Timestamp of when you sent the invite
• Your project ID

so they can check their email delivery logs on their end that's not something visible from the dashboard.