A visitor is stuck at the sign-in page or never received their link. Restricted help centres only let in work emails from domains you've approved — here's how to spot what's blocking them and fix it.

## Checks and fixes

### Check 1: Check whether their email domain is on your allowed list

Open **Settings** and select **Visibility**. If **Restricted to specific email domains** is selected, look at **Allowed email domains** and confirm the visitor's domain is listed (for example, `acme.com`). Domains are matched exactly — `acme.com` does not cover `acme.co.uk`.

![Check whether their email domain is on your allowed list](https://help.supportpages.io/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NTIzMywicHVyIjoiYmxvYl9pZCJ9fQ==--d75db06ec66b3e9daa1086ffefe4e0cfecfb6b81/step_0.png)

### Check 2: Add their domain if it's missing

Type the missing domain into **Allowed email domains** (comma-separated if you need several), then click **Save visibility**. Ask the visitor to try again with their work email.

### Check 3: See if they're hitting a domain rejection

When a visitor enters an email from an unapproved domain, they'll see **That email isn't on an approved domain for this documentation. Please use your work email.** If they report this message, their domain still isn't on your list — double-check spelling and add any alternate domains their company uses.

![See if they're hitting a domain rejection](https://help.supportpages.io/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NTIzNCwicHVyIjoiYmxvYl9pZCJ9fQ==--e2f0827b8dc72ea87656bd3ba193d66737fa438e/step_2.png)

### Check 4: Ask them to check spam for the sign-in link

After they enter a valid **Work email** and click **Email me a sign-in link**, they should see **Check your email** with a confirmation that a link was sent. The email subject starts with "Your sign-in link for" followed by your project name. Have them check spam or promotions if nothing arrives within a minute or two.

![Ask them to check spam for the sign-in link](https://help.supportpages.io/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NTIzNSwicHVyIjoiYmxvYl9pZCJ9fQ==--2aa0802ed36418095c74f5529a0c55bea96857be/step_3.png)

### Check 5: Have them request a fresh link

Sign-in links expire after 15 minutes and work only once. If they already clicked the link or waited too long, they'll be sent back to request a new one with a message that the link is invalid or expired. They can enter their email again on the sign-in page to get a replacement.

### Check 6: Wait if they've tried too many times

After several rapid attempts from the same email or network, the visitor may see a "Too many requests. Please wait a few minutes and try again." message. Ask them to pause for about 15 minutes before requesting another link.

## Tips

- List every domain variant your customers use — including regional domains like `.co.uk` — so contractors and partners aren't locked out.
- Tell visitors to use their company email, not a personal Gmail or Outlook address.
- Suggest they tick **Keep me signed in on this device** so they won't need a new link every visit.

## Summary

Most access issues come down to a missing email domain or an expired magic link. Check **Visibility** settings first, then walk the visitor through requesting a fresh sign-in link from their work inbox.