我已发送了一封主题为“”的邮件。
但是在消息的源代码中，该行如下所示：
[BILLING #PHY-945-49853]: [Ticket #12622] Payment Method
但是在消息的源代码中，该行如下所示：
Subject: =?UTF-8?B?W1NBTEVTICNCQk4tOTM1LTM3OTE3XTogW1RpY2tldCAjMTI2MjJdIFBheW1lbnQ=?=
=?UTF-8?B?IE1ldGhvZA==?=
它是以Base64编码的。我该如何使用php解码它回到原始的英文主题行？我已经试过使用php base64_decode($subject)，但它无法将其解码为原始主题([BILLING #PHY-945-49853]: [Ticket #12622] Payment Method)。
我还附上了一个样本电子邮件消息：
Return-Path: .........
X-Original-To: ..........
Delivered-To: ........
Received: ......
X-DKIM: ........
Received:....
To: ....
Subject: =?UTF-8?B?W1NBTEVTICNCQk4tOTM1LTM3OTE3XTogW1RpY2tldCAjMTI2MjJdIFBheW1lbnQ=?=
=?UTF-8?B?IE1ldGhvZA==?=
From: =?UTF-8?B?U0FWVllFSE9TVElORyBTQUxFUw==?=
X-Priority: ..
X-MSMail-Priority: normal
X-MimeOLE: Produced By Kayako Fusion v4.01.204
X-Mailer: Kayako Fusion v4.01.204
Reply-To: .......
Date: .....
Content-Type: multipart/alternative;
boundary="=_1.64496c432f57488924404b338155a2d7"
MIME-Version: 1.0
Message-Id: ....
这是一条MIME格式的消息。如果您看到此消息，说明您的邮件阅读器不支持此格式。
--=_1.64496c432f57488924404b338155a2d7
Content-Type: text/plain;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
------------------------------------------------------
Support Center:
Content-Type: text/html;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline