为什么有的外企里中国员工之间还要发英文邮件？

因为在外企内部，邮件是被当做一种比较正式类文件，往往记录着一些工作事务上信息，多数情况下也被当做一种证据或者记录（record） 。外企英文作为工作语言，所以写邮件也是要用英文来写。

英语商务邮件写法？

Dear Mr. Thomas,

I am writing to (直接引出写信的目的）thank you for （表明谢意的常用方式）the hospitality you extended （承蒙款待）on my recent visit to your country/company. The delightful and memorable dinner （愉快而令人难忘的晚餐）at your headquarters brought to mind again the close relationship between our two companies. I look forward to developing that relationship to the mutual benefit of our organizations.

Yours sincerely,

Sam

Sales Manager