As others have said - be very careful as to meeting their requirements when you decide to put your notice in to your current employer.
Even the joining e-mails are vague in this respect. You need to ask the right questions to the joining team. I am thinking, in particular, of licence currency (LPC - they don't seem to be aware of ATQP in Europe where the IR is signed every 12 months) and release letter from employer (very vague on the e-mails).
Particularly relevant if they give you a start date that is just over your notice period to current employer.
Welcome to the Middle East.