Hi, My problem is:- Thunderbird filter on an address book not working with the "Additional Email" field only the "Email" field. Just to check I swapped the email addresses around between the Email and Additional Email and yes it still only filtered on the Email field. So how do I get it to filter using the Additional Email as well as the Email field. My only work around is to split the entries into two and only use the main email field in the address book but surely the whole point of having an Additional Email field is to not have to make duplicates if the person has more than one email address. Thanks Andy Using thunderbird v68.12.1