No problem. It used to be possible to use sub-addressing for your sandbox accounts.
So you could make a dedicated email address like:
sandboxale@gmail.com
Then you could use 'sub-addresses' like this:
sandbox+001ale@gmail.com
sandbox+002ale@gmail.com
...
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:
sandbox.0123456789wwr@gmail.com
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:
sandbox.0123456789wwr@gmail.com
sandbox0.123456789wwr@gmail.com
sandbox01.23456789wwr@gmail.com
While an email sent to any of those addresses will always go to sandbox.0123456789wwr@gmail.com.
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.