My friend didn't know that an agent gave him a fake work permit. He was not stopped at the Calcutta Airport and was cleared to board the Emirates Plane to Dubai.
After reaching Dubai Airport T-3, the immigration officer said the visa is not matching on their system and he was deported on the first Emirates plane back to Calcutta.
How did the immigration officer check the visa in Calcutta and allow him to travel? And if the visa was fake then is it possible to book flight ticket?
Typically, at the point of departure, it is only the airline that checks if the person to fly has the necessary documentation to enter the country of destination. They may or may not have access to systems to verify the validity of the visa - but this is also not their task to do. All they need to check is if they the documentation is "obviously" not enough.
The home-country immigration officer will only check the right to leave the home country.
Booking a ticket has nothing to do with having a visa - you can book a flight to where ever you want. The airline just won't allow you to board if you don't show any proof at the time of departure.
Immigration officers from the country you are leaving usually do not care much. I guess some might do something if they notice a problem but checking whether you are likely to get in trouble later on is not their mission. Note that some countries don't have any formal immigration check on exit…
Airlines everywhere do check whether passengers have appropriate documentation for their journey but that's mostly to avoid being fined by the destination state, not to help travellers. So what airlines have to do is merely checking that the visa “looks” right, to the extent required to avoid liability if a passenger is refused entry afterwards. They do not and cannot check if your name is in one database or another or whether you will actually be granted entry.
Do note that there are countless combinations (hundreds of potential destinations, each with several types of visas and different sets of visa requirements) and it would be very complex to check them thoroughly, let alone ensure that countries share information with all other countries on the globe.
An important point that must be said. A visa is not a right to enter a country - a visa is merely a document that allows you to reach the point of entry. The final decision is still in the hands of the immigration officer.
This is true universally, not just in the UAE.
As such, the airline or check-in agent can only confirm the document, they cannot guarantee you entry. They are doing a "best effort" check.
As fake employment agencies and visas are a common problem, the Government of India's Ministry of Overseas Indian Affairs has a special website that lists all authorized recruitment agents and those that are on a watch list for various complaints. I would suggest you make sure whomever you are dealing with is authorized and in good standing.
