-mase usage

hi,

i just want to know the rules on using the form 〜ませ e.g. いらっしゃいませ、くださいませ。

when should i use that form and what do you call such verb form?

thanks

Unless you are a shop assistant or do the announcements in department stores I doubt you'll find yourself ever having to use that form.

i use it in my emails to my boss..
e.g. 書かないでくださいませ。

is it wrong?
because i think that 書かないでください。 is not that 丁寧..

書かないでくださいませ。 ... is polite, but I would say it is not commonly used in business occasions. It is used more for more formal (in the sense of stiff) occasions. And actually, if someone asked me that, I would take it as a "definitely NO!" though it sounds polite on the face, it conveys a more definitive meaning, and can be (in substance) more curt, almost like an order. (It is a bit like saying "It would be appreciated if you don't write" in a flat tone.)

For business context, I would suggest:
書かないでいただけませんか (Wouldn't you please not write it?)
書かないでいただけますか (Would you please not write it?)
as polite requests. Since those are *questions*, they tend to be more roundabout, thus polite, than 書かないでください (Please don't write.)

thank you very much for your reply.

I just thought that くださいませ is more polite than ください.

I will not use くださいませ in my email again.

for example the verb　送る
which is more polite:
お送りください
お送りいただけませんか？

お送りいただけませんか is far more polite and is the norm for requesting people very politely to do something in business correspondence etc. It's like saying in English "Would you please do me the favour of....."