A puzzle: Apple devices that cannot access a particular website?

1

I’ve got a client who cannot access his website or email via the Mail app on any of his Apple devices. This is a new problem that began about a 6 weeks ago.

In terms of accessing his website, I’ve had him try accessing via multiple Apple devices (2 Macs, an iPad, an iPhone), multiple browsers. With mixed results. Mostly seems to not work. On the Mac I had him try changing DNS, no effect. Had him confirm that Private Relay was off. The problem has persisted in several locations across different methods of internet access.

His email has also stopped working on his Apple devices set-up in Apple Mail. Service is provided via the same web host and worked previously with no issues. I use the same host and have no issues with my email using the same settings in Mail.

Thoughts?

Editing to add: I’ve had numerous Apple users test the site, no problem loading from any devices.

2

Firewall on the server, being triggered by a device misconfiguration? If his Mail got misconfigured, for example, it can fail logins at an amazing speed.

3

Try creating a new User on a Mac,
Create a mail accoint for the email in question for that User to see if the email works under the new User and the email accout.
If it works, then try re-creating an account for that email on the old user account.