I can’t really show examples because it’s my work email, but I believe Outlook automatically combines any address with the same “name”.
E.g. I have a contact “Accounting” ([email protected]) and another contact “accounting” ([email protected]) and Outlook will clump them together when I sort my emails. It also clumps together my personal email and work email because they are both “w.meri” even though they have drastically different email addresses.