Not sure of every character? Put a wildcard where the unknown characters go and every match is returned.
* stands for exactly one unknown character. Use one * per unknown character.
% stands for any number of unknown characters, including none.
Email examples
example12*@gmail.com => example123@gmail.com, example124@gmail.com, example12a@gmail.com
example%123@gmail.com => example123@gmail.com, example_123@gmail.com, example.user123@gmail.com
Try this wildcard search: example12*@gmail.com
Keyword examples
Keyword search already matches anything after your term, so wildcards are only needed for characters inside it.
keywordt*st => keywordtest123@mail.ru, keywordtost@yahoo.com
keyword%test => keywordtest99@example.com, keyword_tester@yahoo.com, keyword2test@mail.ru
Try this wildcard search: keywordt*st
Tips
A search cannot start with a wildcard. Put at least one known character first.
Wildcards can be repeated and combined, for example example1**@gm%.com
Keep the known part long. A short start followed by % can match a huge number of records and makes the search much slower.