How to know if an offer letter I received from a company in the UAE is legit?

Dear User,

We can't tell you for sure whether the offer letter/company is legit, though by checking on the national economic register, the above-mentioned company was not found.

If you have someone in the UAE, let them call the company's number to make sure the offer letter is legit.

Moreover, please note that the company should be responsible for the recruitment costs. If they ask you to pay for anything, then it is likely fraudulent.