strange chararacter

Outlook 2011. Mountain Lion.

When I answer people with the email as text message (no HTML),

sometimes people receive the text with strange characters.

So I have applied the following instruction read in this forum:

"Manually setting the Text Encoding to UTF-8 (Format -> Text Encoding -> Unicode (UTF-8) does indeed "fix" the problem".

BUT, every time I compose e new message I must apply that? Outlook doesn't remember this settings?

Thanks

Question about Outlook Express