#?SuikaWiki/0.9
[1] [[HTTP]] の [CODE(HTTP)[From:]] 欄は、
利用者のメイル・アドレスを送るのはプライバシー上よろしくないということで、
現在ではほぼ[[ロボット]]専用となっています。

- Your [CODE(HTTP)[From: [[#form:'%cgi-meta-variable(category=>{HTTP},name=>{FROM});':'':'%output(form=>0);']]]]

- [2] [[NN2]] までは送っていたらしいですが、少なくても手元の 2.02 [ja] では確認できません。

- [3] 未だにエラーメイルを [CODE(822)[From]] 欄宛に送ってくる DQN MTA があるみたいです。名前不明。しかも [CODE(822)[[[Received]]]] 欄の [CODE(822)[From]] に [CODE(822)[0]] とか書いてある素晴らしいホスト!
- [4] [[Googlebot]] は [CODE(HTTP)[@]] の代わりに [CODE(HTTP)[(at)]] と書いて送ってきます。もちろん規格違反です。
- [5] 他には、接頭辞 [CODE(HTTP)[[[mailto]]:]] をつけてくる robot もいます。ここ [[URI]] じゃないってば。もちろん規格違反。
[[#comment]]

* 仕様書から
** RFC 1945 (HTTP/1.0) 10.8; RFC 2068・2616 (HTTP/1.1) 14.22 From
>  The From request-header field, if given, [DEL[[INS[{1945}]] should]] [INS[[INS[{2068}]] SHOULD]] contain an Internet
e-mail address for the human user who controls the requesting user
agent. The address [DEL[[INS[{1945}]] should]] [INS[[INS[{2068}]] SHOULD]] be machine-usable, as defined by [INS["]]mailbox[INS[" [INS[{2616}]]]] in
RFC 822 [DEL[[INS[{1945}]] [7] ]] [INS[[INS[{2616}]] [9] ]] [DEL[(]]as updated by RFC 1123 [DEL[[INS[{1945}]] [6] ]] [INS[[INS[{2616}]] [8] ]] [DEL[) [INS[{2616}]]]]:

>
- From   = "From" ":" mailbox

> An example is:
- From: webmaster@w3.org
 
> This header field [DEL[[INS[{2616}]] may]] [INS[[INS[{2068}]] MAY]] be used for logging purposes and as a means for
identifying the source of invalid or unwanted requests. It [DEL[[INS[{2616}]] should not]] [INS[[INS[{2068}]] SHOULD NOT]]
be used as an insecure form of access protection. The interpretation
of this field is that the request is being performed on behalf of the
person given, who accepts responsibility for the method performed. In
particular, robot agents [DEL[[INS[{1945}]] should]] [INS[[INS[{2068}]] SHOULD]] include this header so that the
person responsible for running the robot can be contacted if problems
occur on the receiving end.
 
> The Internet e-mail address in this field [DEL[[INS[{1945}]] may]] [INS[[INS[{2068}]] MAY]] be separate from the
Internet host which issued the request. For example, when a request
is passed through a proxy[DEL[, [INS[{1945}]]]] the original issuer's address [DEL[[INS[{1945}]] should]] [INS[[INS[{2068}]] SHOULD]] be used.

> [DEL[Note: [INS[{1945,2068}]]]] The client [DEL[[INS[{1945}]] should]] [INS[[INS[{2068}]] SHOULD]] [DEL[[INS[{1945,2068}]] not]] [INS[[INS[{2616}]] NOT]] send the From header field without the
user's approval, as it [DEL[[INS[{1945,2068}]] may]] [INS[[INS[{2616}]] might]] conflict with the user's privacy
interests or their site's security policy. It is strongly
recommended that the user be able to disable, enable, and modify
the value of this field at any time prior to a request.

** RFC の部分の License
[[RFCのライセンス]]
* メモ
- [6] [[WinIE]] で [[Webアーカイブ]]で HTML を保存したら出力される [CODE(file)[mht]] ファイル (中身は擬似 [[822]]) では、 [CODE(822)[From: <Microsoft Internet Explorer 5 で保存する>]] というのがついてます。まじで。[[シフトJIS]] で。 ([[WinIE6]] なのに。。。)
- [7] >>6 [CODE(822)[[[Subject]]]] 欄には [[encoded-word]] 使うのに、 [CODE(822)[From]] は生シフト JIS、それも規格違反の場所になんてねぇ。。。