Phishing Investigations and Research
A large part of fighting phishing is knowing how to read an emails headers.
urlscan.io is a great why to find out where those phishing links lead to. *Caution* Don't scan any links that my have personal information. Make sure that you confirmed that they are phishing links. we don't need any more PII out in the open on the internet.
I many use this site to quickly parse email headers, but it also has many other features.
public information about IP numbers, domain names, host names, Autonomous systems, routes etc.