大家好，我仔细浏览了这个论坛，但没能找到有和我一样问题的人。我现在真是急得抓耳挠腮。
情况如下：
- 我在一个 VPS 上部署了 Mail-in-a-Box
- 在另一个 VPS 上部署了 Discourse
这两者运行得都很好。但是，我就是无法让“通过邮件回复”功能正常工作。
我使用的是 POP3 轮询。通过检查 Discourse 和 Mail-in-a-Box 的日志，我可以确认 Discourse 已成功通过 POP3 登录。我也可以直接在 Mail-in-a-Box 上登录该邮箱地址，看到等待 Discourse 收取的邮件回复。但似乎发生的情况是：Discourse 通过 POP3 认证后，没有检测到任何邮件回复，然后就直接退出了。
我的 reply by email address（回复邮箱地址）设置为：reply+%{reply_key}@fiftyshadesof.green
我的 alternative reply by email addresses（备用回复邮箱地址）设置为：jack+%{reply_key}@fiftyshadesof.green
我已经将 reply@ 设置为 jack@ 的别名，但我注意到在邮件头中，邮件可能被作为后者处理。以下是邮件头信息：
Return-Path: <j****x@****.com>
Delivered-To: jack+583cabd428af27911245150bb3679039@fiftyshadesof.green
Received: from b******h ([127.0.0.1])
by ********** with LMTP id 8L3WEQDCEmAEsAAAOOEQUQ
for <jack+583cabd428af27911245150bb3679039@fiftyshadesof.green>; Thu, 28 Jan 2021 13:54:08 +0000
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on ******
X-Spam-Level:
X-Spam-Status: No, score=0.6 required=5.0 tests=DKIM_SIGNED,DKIM_VALID,
DKIM_VALID_AU,FREEMAIL_FROM,HTML_IMAGE_ONLY_28,HTML_MESSAGE,
RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE autolearn=no
autolearn_force=no version=3.4.2
X-Spam-Report:
* -0.0 RCVD_IN_MSPIKE_H2 RBL: Average reputation (+2)
* [209.85.222.175 listed in wl.mailspike.net]
* 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record
* 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail
* provider (j****m)
* 0.7 HTML_IMAGE_ONLY_28 BODY: HTML: images with 2400-2800 bytes of
* words
* 0.0 HTML_MESSAGE BODY: HTML included in message
* 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily
* valid
* -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from
* author's domain
* -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature
* -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at
* https://www.dnswl.org/, no trust
* [209.85.222.175 listed in list.dnswl.org]
X-Spam-Score: 0.6
Received: from mail-qk1-f175.google.com (mail-qk1-f175.google.com [209.85.222.175])
(using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits))
(No client certificate requested)
by ************ (Postfix) with ESMTPS id 10B91A6ACC
for <reply+583cabd428af27911245150bb3679039@fiftyshadesof.green>; Thu, 28 Jan 2021 13:54:07 +0000 (GMT)
Authentication-Results: ***********; dmarc=pass (p=none dis=none) header.from=****.com
Authentication-Results: ***********;
dkim=pass (2048-bit key; unprotected) header.d=****.com header.i=@****.com header.b="aU1Sdycv";
dkim-atps=neutral
Received: by mail-qk1-f175.google.com with SMTP id x81so5267064qkb.0
for <reply+583cabd428af27911245150bb3679039@fiftyshadesof.green>; Thu, 28 Jan 2021 05:54:07 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=****.com; s=20161025;
h=mime-version:references:in-reply-to:from:date:message-id:subject:to;
bh=illVjQUsMQXKmF7F7Mv1ysXAw5aKA0qiK8o4tLS6BMQ=;
b=aU1SdycvYshTO1kKUFq9r3xR0UJrSOh4Met+wcwqEaK7EWb26bJwbMpa850USAmKjY
CajKe2iyRobMDtYg9I7zQVKh1i3cqnc8ve1/hSFnEPW/Nc6zapWJn72fdhsPQGyiBASq
Y5gAIqL6Sz6SaaPAB2i4zcx5I+6jJq/m/mC8o9IxJ3W0YExxQlHc6l+JZR6EqACPccXi
m53fB9qFCsSU1fmS6VgVE+LegvFozjsMeHjTJ3qzjeHyK82NG3UJSmMzDuyad7yJOBYT
4wa13+2ERPlRdPASY/dmWQB6+nCQTQhRhXCNMpzUdOFZTPnVdauj+QpcPGQnnvYHl90w
bBtg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:references:in-reply-to:from:date
:message-id:subject:to;
bh=illVjQUsMQXKmF7F7Mv1ysXAw5aKA0qiK8o4tLS6BMQ=;
b=udoaf8sLd7IeXLppi0FCOTvqdg8fQkCdLsH4EFwxQSTa9fjax1P1/1yIBexxRHi/zw
dSpY+/8L/v+VHN9RDw4q9jn3Xx6hqxFzfSLJcEXMoQ6eyVzbCYKNVUNcNPAZ2/hqgqu8
8XZ5PpYCVUxcsmqSKYcWcbA0JHqGKcJbvTKCugrqeuqByOESSEBzKQS7+xxpFw02yPA4
1TEyW020NBXVHTVy8eSkGTPpHuK4Q159/ewyXx3aLNDGwCruwXXfh32uO48QA+vsU6m9
c0oXiGgAdsodj3+dOOmxAiSqa+wlei7xV1YFQ79uorjb+kZXlFu5jGUrVq7BlL3PeB+j
hn8g==
X-Gm-Message-State: AOAM5332+AyWKnsgCEaYCAgVNKrukhC2+1N032dkVYgN6xcAuJYYTyyQ
7VWcl/WGEEwNN+BKozjToIRQ+cN836UNAl8TFwDzJpbCOq4=
X-Google-Smtp-Source: ABdhPJwKf65r23SSJmH5DRfIi1VOU4fLExuZ/hO/9EBZMDXrK5m6gYotkBSCDvrI3zTNTumMa6CWFULLQ2eqnIeWDFA=
X-Received: by 2002:a37:4590:: with SMTP id s138mr15675696qka.239.1611842046913;
Thu, 28 Jan 2021 05:54:06 -0800 (PST)
MIME-Version: 1.0
References: <topic/19@discourse.fiftyshadesof.green>
In-Reply-To: <topic/19@discourse.fiftyshadesof.green>
From: Jack Lenox <j***********.com>
Date: Thu, 28 Jan 2021 13:53:55 +0000
Message-ID: <CAHy8DYjbnLcMHmqSb=-b2B=6ZMxGmba4eT5r0E0j_c4jJfi5Vg@mail.****.com>
Subject: =?UTF-8?Q?Re=3A_=5BFifty_Shades_of_Green_=E2=80=93_Test_Discourse=5D_=5BSamp?=\n =?UTF-8?Q?le_Category=5D_I_wonder_if_I=27ll_be_able_to_reply_to_the_emails?=\n =?UTF-8?Q?_sent_from_this_one?=\nTo: =?UTF-8?Q?Fifty_Shades_of_Green_=E2=80=93_Test_Discourse?= <reply+583cabd428af27911245150bb3679039@fiftyshadesof.green>
Content-Type: multipart/alternative; boundary="000000000000a3f5e605b9f63853"
为了隐私起见，我对上述内容做了一些脱敏处理，不过目前这只是一个测试环境。
我尝试过取消勾选“使用密钥查找相关帖子”选项，但两种设置都不起作用。
任何帮助都将不胜感激！