Let’s say you want to filter messages sent to foo@example.com and bar@example.com and apply the ‘MyCompany’ label to those messages. You may think that typing the following in the ‘To’ field of the filter will work:
but it doesn’t. It doesn’t work with ; either.
In order to add multiple addresses to the filter you have to separate them with a | or wrap them in parentheses and use OR as the separator. The following are working examples:
The same can be applied when searching email.