Choose a mailbox name you can reuse in testing

The local part is the half of the address before the @ sign. On this site it can use letters, numbers, dots, underscores, plus signs, and hyphens. It has to start and end with a letter or number. It cannot be longer than 64 characters, and it cannot contain two dots in a row.

Make the name describe the test

A name like invoice-preview or signup-ios-beta is easier to return to than a string you will forget. Put the product and the scenario in the name. Leave out customer names, phone numbers, and real account ids. The name is visible to anyone who opens the inbox, and it may be visible to anyone who watches you type it.

One concern per name

If two tests share an address, their messages mix. A code from a password form can sit next to a receipt from checkout, and a person can copy the wrong one. Use a new name when the test changes. The inbox page lists newer messages first and does not know which person you are.

A plus sign is still its own public box

Some mail systems treat a plus sign as a tag on one mailbox. Here, the whole local part is one exact address. billing+april@themailinator.com is not the same inbox as billing@themailinator.com. Both are public. Typing one name will not show the other name's mail.

Write the full address into the other form

The opener on our home page adds the domain for you. The app you are testing needs the full address, name and domain together. If that form rejects the domain, the product does not accept this kind of test address. Forcing it is not something this site can repair. The checklist is a short pass to run before you submit, and reading a verification code covers what to do once the message is on the page.