Vlookup with nested if statement

[colmodoc]

Hi.
I would really appreciate assistance on what I believe will be a nested Vlookup and IF statement.
I wish to compare records in two separate lists using a VLookup. However I want to identify items (using Serial#) that appear in both lists where ownership is different in both lists.
Ownership is identified by email address.
Thank you!
See example:

 

[Fluff]

But is that 365, 2021 or 2019 or another version?