What I mean is that even if you go through the trouble of getting all your papers and blood tests, dammaj is on so-called watchlists, so the yemeni government, in order to remain in good standing with their western backers, have to make a show of throwing out people occasionally. That way they show they are tough on extremism, you get me? If you look in their newspapers, they post annual quotas of people arrested in the fight on extremism. It's how they qualify for aid money.
Think of it as a don't ask, don't tell policy. They are smart enough to figure by now that most brothers who enter yemen with short pants and long beards and the sisters with the niqaabs are hoping to head one place, but they turn a blind eye, so long as you don't make a show of your intentions. They won't ask you if you're going, and you don't tell them where your headed, pay your hefty fees, and pass through.
As for paying legally, in a country like yemen, there is no such thing. With no sound bureaucratic system, you are paying thousands of dollars to shady middlemen, who pocket half of it, and give the other half to their contacts. While you end up with no iqaamah. If you enter legally through a mahad, they won't release you or your passport, because if they do, they lose the money you are paying them to keep you in the country, so they essentially hold your passport hostage to prevent you fro going to the D. I've heard of brothers who actually had to fight for or steal their passports from so called salafi mahads!!! I could tell you nightmare story after nightmare story about brothers bein ripped off, but I don't have the time, and it might take me a few days.
The truth is, because their system is so whacked, paying the fines at the end of your stay is actually the only valid way of making sure the money gets to the officials instead of the crooks. Because when you pay your fine, they have an actual system of calculating how much you owe, and an actual release process. To give you an example, I paid 500 USD to a guy who was supposed to give me an iqaamah, which to this day, I have no idea that he ever made. Upon leaving, I had to go the officials and pay a fine on the 9 months I was in Yemen anyway, so I ended up paying double, once to a crook for something I thought was gonna make me legal, and then second to an official for something that cleared me of being illegal!