Typosquatting is an impersonation technique frequently used to target employees. In this scenario, attackers buy a domain that is very similar to the company's domain and use it to send spear phishing emails to the company's employees. For example, attackers targeting Barracuda employees would buy baracuda.com (one ‘r' is missing) and try to trick employees of the company to send them sensitive information or wire money. Some attackers even register the same domain in non-Latin alphabets (e.g., Cyrillic), for example, Baггacuda instead of barracuda (the Cyrillic letter ‘г' replaced the Latin ‘r').
Some email security solutions do provide protection against typosquatting. This is typically done by creating rules that try to find common letter replacements or by trying to find similarities between the URL of the company and the URL of the sender. While this type of protection should be in place to protect your business, it is only partially effective in protecting you from spear phishing attacks.