假如客户询问的日期是昨天，需要产品A
Dear Sirs,
In response to your letter of 27th Dec enquiring for product A, we are afraid to inform you that we haven't had the product you are asking for.However, there are some other products we can offer which are similar to product A and can also meet your demand. Attached there are our products' details. If you find any of the items interesting, please let us know
as soon as possible. We shall be glad to send you quotations and samples upon receipt of your concrete enquires.
Looking forward to your early reply.
Best wishes,
yours faithfully,
John
因为不知道你们做的是什么产品，不能写的很符合。你可以根据实际情况修改。
像这种没有对方要求的货物时，回复的主旨是要在表达自己没有他们产品的同时提供你们能够提供的替代品，争取业务的发生。
希望对你有所帮助。本回答被提问者采纳