MIME and Quotedprintable

关于MIME的介绍，from http://en.wikipedia.org/wiki/MIME

Multipurpose Internet Mail Extensions (MIME) is an Internet Standard that extends the format of e-mail to support:

• text in character sets other than US-ASCII;
• non-text attachments;
• multi-part message bodies; and
• header information in non-ASCII character sets.

Virtually all human-written Internet e-mail and a fairly large proportion of automated e-mail is transmitted via SMTP in MIME format. Internet e-mail is so closely associated with the SMTP and MIME standards that it is sometimes called SMTP/MIME e-mail.[1]

The content types defined by MIME standards are also of importance outside of e-mail, such as in communication protocols like HTTP for the World Wide Web. HTTP requires that data be transmitted in the context of e-mail-like messages, even though the data may not actually be e-mail.

MIME is specified in six RFCs : RFC 2045, RFC 2046, RFC 2047, RFC 4288, RFC 4289 and RFC 2077.

关于Quoted-printable的介绍，from http://en.wikipedia.org/wiki/Quoted-printable

Quoted-printable, or QP encoding, is an encoding using printable characters (i.e. alphanumeric and the equals sign "=") to transmit 8-bit data over a 7-bit data path. It is defined as a MIME content transfer encoding for use in Internet e-mail.

一些其它有用链接：

http://www.weiw.com/tech/luanma/luanma08.html
http://www.lupaworld.com/441/viewspace_220.html

我的分析，到http://www.motobit.com/util/quoted-printable-decoder.asp，提供在线的解码。输入：

<P>Dear Amazon member, <BR><BR>Due to concerns we have for the safety and =
integrity of the Amazon community we have issued this warning. <BR><BR>Per=
the User Agreement, Section 9, we may immediately issue a warning, tempor=
arily suspend, indefinitely suspend or terminate your membership and refus=
e to provide our services to you if we believe that your actions may cause=
financial loss or legal liability for you, our users or us. We may also t=
ake these actions if we are unable to verify or authenticate any informati=
on you provide to us. <BR><BR>Please follow the link below: <BR><BR><A hre=
f=3D"http://rds.yahoo.com/_ylt=3DA0geurgnV4VEPnoB98hXNyoA;_ylu=3DX3oDMTE5a=
XJmaGJ2BGNvbG8DZQRsA1dTMQRwb3MDMTIzBHNlYwNzcgR2dGlkA0Y3NTFfMTA4/SIG=3D12hh=
jkhah/EXP=3D1149675687/**http://www.google.com/url?q=3Dhttp://211.94.240.2=
1/_us/obidos/index.html?ref=3Dpd_irl_gw_r/102-8758036-5777720?opt=3Doa&pag=
e=3Drecs/sign-in-secure.html&response=3Dtg/recs/recs-post" target=3D_BLANK=
>http://www.amazon.com/exec/obidos/sign-in.html</A><BR><BR>and update your=
account information. <BR><BR>We appreciate your support and understanding=
, as we work together to keep Amazon market a safe place. <BR><BR>Thank yo=
u for your attention on this serious matter.</P>
<P><BR>Regards,<BR>Amazon Safety Department<BR><BR><BR>NOTE: This message =
was sent to you by an automated e-mail system. Please don't reply to it. A=
mazon treats your personal information with the utmost care, and our Priva=
cy Policy is designed to protect you and your information.</P><FONT
size=3D=
2></FONT><FONT face=3DArial size=3D2>
<P>&nbsp;</P></FONT>

输出为：

<P>Dear Amazon member, <BR><BR>Due to concerns we have for the safety and integrity of the Amazon community we have issued this warning. <BR><BR>Perthe User Agreement, Section 9, we may immediately issue a warning, temporarily suspend, indefinitely suspend or terminate your membership and refuse to provide our services to you if we believe that your actions may causefinancial loss or legal liability for you, our users or us. We may also take these actions if we are unable to verify or authenticate any information you provide to us. <BR><BR>Please follow the link below: <BR><BR><A href="http://rds.yahoo.com/_ylt=A0geurgnV4VEPnoB98hXNyoA;_ylu=X3oDMTE5aXJmaGJ2BGNvbG8DZQRsA1dTMQRwb3MDMTIzBHNlYwNzcgR2dGlkA0Y3NTFfMTA4/SIG=12hhjkhah/EXP=1149675687/**http://www.google.com/url?q=http://211.94.240.21/_us/obidos/index.html?ref=pd_irl_gw_r/102-8758036-5777720?opt=oa&page=recs/sign-in-secure.html&response=tg/recs/recs-post" target=_BLANK>http://www.amazon.com/exec/obidos/sign-in.html</A><BR><BR>and update youraccount information. <BR><BR>We appreciate your support and understanding, as we work together to keep Amazon market a safe place. <BR><BR>Thank you for your attention on this serious matter.</P>
<P><BR>Regards,<BR>Amazon Safety Department<BR><BR><BR>NOTE: This message was sent to you by an automated e-mail system. Please don't reply to it. Amazon treats your personal information with the utmost care, and our Privacy Policy is designed to protect you and your information.</P><FONT
size=2></FONT><FONT face=Arial size=2>
<P> </P></FONT>

看看这里的URL，就是利用了URL Redirection。