What’s the purpose behind this phishing attempt?

As probably all of you, I got an email that was intended as a phishing attack.

The HTML version of the email was pretending to be a Facebook email of a security warning.

phishing image

The links do lead to Facebook, for an account-switching crafted URL. I get that one.

However, the text version of the email has something like this:

mailto:xxx@stanforduni.com;xxx@massachusettsins.co.uk;xxx@e-irosky.me;xxx@harvarduni.org;xxx@univofcambridge.eu;xxx@univofoxford.com;xxx@yandex.ru;xxx@yandex.ua;xxx@yandex.kz;xxx@yandex.by;xxx@yandex.com;xxx@mail.ru;xxx@yahoo.com;xxx@aol.com;xxx@gmail.com 

(I redacted out usernames from those addresses.)

Some of those names seem to be related (maybe the same person across multiple domains?). Some others seem generic but on a similar vein (mostly universities).

My question is: what’s the purpose of this "attack"? Clicking on those would trigger my email client to prepare an email for all those addresses. What does an attacker gain out of this?