Typosquatting

Typosquatting, also called URL hijacking, a sting site, or a fake URL, is a form of cybersquatting, and possibly brandjacking which relies on mistakes such as typographical errors made by Internet users when inputting a website address into a web browser. They then use this "fake" domain name to email employees and plant phishing attacks. Please do not interact with any emails from the "imposter domain".

More info https://youtu.be/Wss49XLNXfl

Who is domainname.com

You receive an email from an xyz@abc.com and want to check whether abc.com is a legit company/business.

Go to https://www.whois.com/whois/

Type abc.com in the search box and click search.

You will find the Domain Information like who the registrar, registration, expiry and updated dates, status and name servers. You also find the registrant, administrative  and technical contacts information as well. 

This is a good tool to use to check the validity of a domain like that which comes from your email as well. 😉👌🏼