No problem. It used to be possible to use sub-addressing for your sandbox accounts.
So you could make a dedicated email address like:
Then you could use 'sub-addresses' like this:
Any email send to a sub-address goes to the parent email acc, while Sandbox would consider each sub-address to be a unique email, and allow you to set up a fresh Sandbox acc. This meant you didnt have to go setting up a dozen different email accounts, just one.
But Apple no longer supports sub-addressing which sucks. So the trick you can use now involves putting a period in your email address.
So make an email account like:
gmail ignores the position of the period, but Apple considers the email address to be unique if the period is repositioned.
So you can set up separate sandbox accounts with:
While an email sent to any of those addresses will always go to firstname.lastname@example.org.
Its less elegant than sub-addressing but it works, and saves you having to find a dozen different email addresses to do your sandbox testing.