Tools
Below is a list of tools that I use on a regular basis for my cybersecurity work. I created NONE of these tools, all credits go to their respective authors. I simply wished to compile them for my own convenience and anyone else's curiousity. This is not a particularly comprehensive list.
Email Security:
VirusTotal is an excellent tool that can scan URLs and files. It reports back with results from dozens of independent vendors, community scores, detail analyses, and other useful information.
URLScan.io is not as robust as VirusTotal in terms of scanning a URL, and cannot accept files, but it does provide a preview of the site being scanned. For those without easy access to a VM/sandbox, this can come in handy.
MX Toolbox contains a myriad of options for analyzing an email, from basic MX record lookup to header analysis. This is useful for analyzing aspects of the phishing email itself, such as its origin.
WHOIS lookups are used to gather registration details about a domain. This is very useful for determining the age and ownership of a website.
I also make liberal use of virtual machines when analyzing potentially dangerous sites or files. Windows Sandbox is a convenient option, though I also use Oracle VirtualBox.
Data Privacy
IntelTechniques has some of the most useful information about data privacy around. I strongly advise those looking to reduce their digital footprint to visit this site and read through its resources. I removed my personal information from many data brokers thanks to its guides, many of which were free.
Have I Been Pwned is another great resource for those seeking to understand how much of their data exists online. Use this tool to check if your email address has been included in any major data breaches, along with more details about the respective breach(es). The site's owner, Troy Hunt, is a security expert with some very interesting written works.
OSINT Framework is a large compilation of tools used for open source intelligence (OSINT) gathering, which I reference often. If you are searching for someone (or yourself), this is a good place to start looking for tools. The tools available search public records to find information about a target, hence the "open source" bit.
I have found that data brokers such as Spokeo and ThatsThem have a surprising amount of information on people living in the United States. These are tools that I use to check who owns a phone number or email address, see who lives at an address, and search for other information about people.