If you can see random letters and numbers in the sender’s address then this should start to ring alarm bells. Equally, emails saying: ‘there’s been suspicious activity on your account’ or ‘you sent a payment to XXX, if you didn’t make this payment click here’ are there to cause panic.
Fraudsters prey on customers acting in panic. The fear that someone has hacked your account based on what the email is saying will cause people to click that fake link without thinking.
You can also see where the link will take you if you hover over it, just don’t click it by accident!