返回目录：范文示例
如果收信人不确定，百可以写To whom it may concern,
结尾最常度用的内是best regards或者thank you for your time，两个同时用容也可。
落款用yours sincerely, XXX
商务信函或商务函电还是很有讲究的，尤其是在尊贵的客户面前或者是接触不深，一定要谦虚谨慎。给你看篇例子：
Promotion Lerrer 推销信函
Dear Sirs, We have just introduced our new refrigerator to the market , and are enclosing sales promotional literature to give you full details . No doubt your customers will appreciate the opportunity to purchase this fine product and with this in mind we are enclosing an order form for you to complete and return to us without delay . You will received a special introductory discount of 10% which we can maintain until November 20 .
Yours faithfully , ( Signature )
不过，对于熟悉的老客户，语气可以适当缓和，偏向口语化，具体的其他几位回答者所说的都可以。
供你参考！e799bee5baa6e997aee7ad94e58685e5aeb9338
邮件的开头，在称呼之后，通常会问候一下：
1.Hope you are well.
2.Have not heard from you for a long time, hope everthing is going well with you.
3.How have you been recently?
4.How are you doing recently?
5.It was good to hear from you. I am very well, hope you are the same.
6.It is my great honor writing to you.
扩展资料:
1.基本的英文书信格式应包括四大部分：日期，称呼，正文，和落款（包括敬语）
例如：e5a48de588b67a64333
October,16,2011（右起顶格）
Dear Jimmy（左起顶格）
I'm glad to receive your letter...（正文，开头空四格）
Yours Sincerely,
Jack（右下，包括敬语和落款）
2.信件开头称呼：
(1.)写给朋友，用"Dear+名"。如Dear Megan。
(2.)写给家人，用"My dear+ 称呼"。如My dear father。
(3.)公务信函。如果不知道收信人是男还是女，用"Dear Sir or Madam"。如果收信人是男的，用"Dear Mr + 姓"，如"Dear Mr Lewis"。 如果对方是女的，用"Dear Mrs +姓"， 如"Dear Mrs Hatton"。
(4.)也可以用"头衔/职位+姓/姓+名"。如Dear Prof. Tim Scales,Dear Dr.John Smith。
参考资料：百度百科-英文书信
开头如果百知道写给谁，可以用度Dear xxx，如果不知道写问给谁，可以用Dear Sir/Madam或者答To whom it may concern,中文是“敬启者”的内意思。
落款可以容用Yours Sincerely或者Best regards.