You also shouldn't invite random strangers into your accounts. Scammers are rampant online. People want your data to hack your accounts, sell to businesses, or steal your identity. If you know what to look for, it can be exceptionally easy to identify when someone is trying to steal from you.
Email scams are one of the primary methods by which scammers attempt their "business". They'll claim they are an official government entity, bank, or other insurance company, and say that you need to send them your social security number, phone number, and other such data. If you find one of these in your inbox, don't even bother clicking on it. Keep an eye out for bad grammar, weird text blurbs, and a lack of official documentation.
Additionally, do not click on random links. One tactic scammers will try is they will send you an email that has hardly any information that will take you to a website with potential viruses. Don't fall for it!
Avoid giving any information to someone who doesn't have the authority to ask. They may be trying to go phishing for your data. While they aren't inherently scammers, they will take your info and divvy it out to the highest bidder. This forces unwanted emails into your face every time you log in to your account.
While these are just a few examples of scammers and criminal behavior online, this can give you an idea of what you should look for. If your employees use an official company email, make sure they are aware of scammers so they don't give out information to someone they shouldn't. Avoiding internet scams should be part of your company's training regimen.