Is this xxxxxxxx@PrivateRelay.appleid.com just for one-time use?

Hi,

Earlier I installed an 3rd party app from the Apple Store using a privaterelay.appleid.com email address. Since the login token has expired in this app, I haven’t been able to sign in again.

On my iPhone (iOS 26), I checked the email address that was used during the original registration. I requested a password reset from the third-party app mentioned earlier, but the reset email never arrives in my iCloud mailbox.

My question is: is this a one-time use email address, or should it still be active today? I tested it by sending an email to that address, but it does not get delivered.

I’m asking because while I understand the security benefits of protecting an email address this way, it may cause difficulties later - for example, if I request a password reset link or need to receive other important messages.

Thank you!