在正式的邮件、书信、通告中，如不能确定具体收件人的身份或姓名，则可以用 “To whom it may concern” 来开头，它相当于汉语正式信件中的表达 “敬启者”、 “致有关人士”。比如，如果一位顾客想给一家公司写投诉邮件，则可以用 “To whom it may concern” 来称呼售后服务部门的工作人员。在正式信函中，“To Whom It May Concern” 中的每个单词的首字母往往会大写。

例句

1.

To Whom It May Concern,

I am writing to complain about a product I recently purchased. Not only had it obviously been previously used, it also had no instruction manual.

致有关人士：

我想对近期购买的一件产品进行投诉，特此致信。该产品不仅已被使用，而且缺少使用说明书。

2.

To Whom It May Concern,

I am writing to confirm that Miss Ju was employed as a Sales Manager by ABC Trading from 2nd September 2008 to 14th October 2012.

敬启者：

此信确认鞠女士于2008年9月2日至2012年10月14日在 ABC 贸易公司担任销售经理一职。

3.

To Whom It May Concern,

I am writing to express my interest in attending the Annual Golf Conference on 14th October and would like some more information on the prices of tickets.

敬启者：

本人有意参加于10月14日举办的年度高尔夫大会，特此致信了解更多有关票价的信息。