Companies make this hard, a bit like various email scams where legit company communication comes from seemingly random domains (hello paypal). Often the company is legit, but theres no public contact that knows anything about the recruiter thats working for them.

Healthcare companies are the WORST at this - they will send you legitimate email from h34lthc4re.biz with a heart-happy-health.phishing.info link that you HAVE to use - and it's all legit.