Bit of an odd Email incident

[Carruthers]

A couple of days ago I found an Email in the junk folder under the name of a neighbour.

I had a look at it and, although his name was correct, it came from an address I didn't recognise.

The content was a spam link apparently originating in Finland.

I ran both an AVG virus and a Malware Bytes check and nothing untoward was revealed.

Any ideas if my neighbour's address book has perhaps been compromised?

ETA This happened once before some months ago with an Email supposedly from a former work colleague and it's rather puzzling.

Any thoughts on the subject?

Ta!