这是骗子吗？乌干达客户要求这样的付款方式，我能答应吗？？？

dear thank you for your reply. our detailed order will follow shortly. but we should first discuss the payment terms. payments: for such a long term business we insists on oa open account terms with insurance credit coverage and payment terms to be direct collection via tt, 90/60 days from the b/l date. in the meantime let us know whether your import and export bank of china or insurance company??is ready for??our application of export credit insurance as all our orders will be under credit insurance. we shall then send the our details including the audited financials for your onward transmission to your insurers or import bank of china to enable them investigate the creditworthiness of our company that will lead to the possible opening of a credit line for the buyer. regards 我刚出来外贸，看得不是很懂，大概知道什么意思。由于我们这款产品利润很低很低，所以我回复we prefer tt ,30% deposit,70% balance before delivery. 然后过了好些天，他又回复we want oa under export credit insurance 请高手们告诉我这个客户大概是表达什么意思，我该怎么回复？？ thanks in advance!