dono ?

a new japanese woman employee has joined my team. When she mails me, she adds -dono after my name. Now, I know about -san which from my understanding means ''Mister -'', but it is the first time i've heard -dono. She is quite older than me (about 15years) but I'm her direct manager since she works for my busho.

I'm wondering what is the meaning of this -dono and what kind of relation does it imply ? Is it appropriate use considering the situation ?

"dono" is used when we do honor to a great person(or an older person) in written japanese.

It is rarely used in general conversation

"dono" “a comes from “a—l(lord). It has more respect than "sama" but is used for a (older) male only.

JY,

''-Dono'' is commonly used to address both men and women when corresponding on business or writing official documents. Whether it shows more respect than -sama is debatable. Kojien dictionary says that it shows less respect than -sama, but some organizations seem to educate their employees saying that -dono can by used among most colleages. The following is for reference.

http://dictionary.goo.ne.jp/leaf/jn2/159745/m0u/%E3%81%A9%E3%81%AE/
http://oshiete.goo.ne.jp/qa/1246177.html

-dono is generally used to adress co-workers with respect in written language(i.e. Emails, documents, letters etc).
-san would mainly be used in speaking language, but may be unpolite in some situations, depending on the rank of the person you are talking to.
-sama too is used in written language but is used towards people out side of the company (i.e. customers, progect members from other companies etc)
There is a costum to think that customers and people from other company are higher in rank so in that way, using -sama to a person inside the company would be inapropriet.