今天看书看到Domino的Journaling，说到Journalled message可以被送到local database或一个mail-in database，那么这个mail-in database是什么呢？在IBM网站上只找到一点关于如何配置mail-in database的内容，没有详细说明它的特殊之处，于是求助于万能的狗狗，果然没让我失望：
 
A mail-in database is essentially a Lotus Notes mailbox (Notes database based on the Mail template) that is not tied to any particular Lotus Notes user account (i.e. does not have its own ID file and password). A mail-in database has a unique UserID ("short name") associated with it and its own e-mail address.

Each user requires only one Lotus Notes account (in their name). If there is a need for a separate mailbox with its own e-mail address that can be shared among different users (example: [email][email protected][/email]), then a mail-in database is created rather than additional Notes account. The access to this mailbox is controlled through its Access Control List (ACL) which contains the names of the Notes users that are allowed to open the mailbox using their own ID files and passwords. No separate password is required to accessed a mail-in database.
 
基本意思就是说它和普通的Note邮箱区别不大，特别之处在于它不与任何的用户ID绑定，也就是说，虽然它也有自己的地址，但是并不专属于某个用户，所以mail-in database通常用来做公共邮箱，例如 [email][email protected][/email]，通过ACL来控制用户对这个邮箱的访问。