[TYPO3-english] Garbled mail from mailforms

[Lukas Mattsson]

Hi, I have a problem with the mail received from the mailform in one of 
my TYPO3 installations. The mail works if it consist of no more than 
English characters and numbers, but fail if I use special characters, 
like "å", "ä" and "ö".

The special characters are substituted by question marks, and the entire 
message is often repeated several times.
I use TYPO3 4.5.3
I've tried to change mail transport from php to sendmail and smtp, but 
the problem persists. I have also tried multiple e-mail clients, to rule 
out client problems.

How come?
Best regards, Lukas