客户之前一直在我们这里下单，但是最近一两年没下单了，是客户的原因还是我们产品或者价格的原因，我们想跟客户保持长久合作，请用英文写一封邮件？

Dear [Customer Name],

I hope this email finds you well. I wanted to reach out and express our gratitude for your past business with our company. We truly appreciate your support and loyalty.

I noticed that we haven't received any orders from you in the last year or two, and I wanted to touch base and see if there was anything we could do to better serve you. Was there a specific reason you haven't ordered from us recently? We value your feedback and would love to know how we can improve our products or services to better meet your needs.

We understand that there are many options out there, but we hope that we can continue to be your go-to supplier. We value our relationship with you and strive to provide the best quality products at competitive prices.

Thank you again for your past business, and we look forward to the opportunity to work with you again in the future.

Best regards,

[Your Name]