I am from Germany and my name contains a special character (ä). If I send a mail the from-name in the mail header is encoded like following:

From: "=?ANSI_X3.4-1968?Q?Werner_Sch=3Fffer?=" <werner@xyz.net>

ANSI_X3.4-1968 seems to be a very strange character set. Nevertheless the result is, that my name is not shown correct. (Sch?ffer insteed of Schäffer)

Writing my name into subject it is encoded like

Subject: =?utf-8?Q?Werner_Sch=C3=A4ffer?=

This is fine and the name is shown correctly.

Questions:
Is this a bug or is it customizable?