我对邮寄到gmail的后缀有问题。从我的VPS发送到gmail的每条消息都有一个垃圾邮件标志。 SPF，DKIM，DMARC-通过。我没有任何RBL。我不知道为什么会这样。有谁知道为什么吗？
在文件中：/etc/postfix/main.cf我有：
# network settings
inet_interfaces = all
mydomain = mydomain.com
myhostname = s1.mydomain.com
邮件标题：
Delivered-To: account@gmail.com
Received: by 2002:ac9:1144:0:0:0:0:0 with SMTP id 62csp776917ocg;
Sat, 15 Jun 2019 08:02:00 -0700 (PDT)
X-Google-Smtp-Source: APXvYqyvuuyVZSHWSbb8v+5zv5BwLnq5mjZOn4expDs6idszN677R4Ryy3gESQTNjg/1TQVEJgQp
X-Received: by 2002:a5d:49c3:: with SMTP id t3mr21524370wrs.147.1560610920132;
Sat, 15 Jun 2019 08:02:00 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1560610920; cv=none;
d=google.com; s=arc-20160816;
b=MGPesmmfN2nNKVuPVRHIrvOJDpauRx5rTyCdUSYuK0nVkBp7ur4l6zteyv0L499i8x
S4MaSN1QSy3l0KGI/e3u6kC7vN9vgDv0e8XIn1xN4c6Ydkmjdsa9hQULF2A8uXME7mZz
MG00owe1Ibm+Nb73pikVZHYcyV5miL5nyBcyT4GRM0/FiGTBsKOc/+GQ6F+XwDznEs7P
d4heSdnQJNoW2W5Z1SoiUON3izfHY8XEOpTT14ukvo4uXuFbTCg5ksjGizzRHAMlsrGp
N2keAslaoETIIxrKm/54gn79mBpw6KhYGd4rjiCY/UMPaZhZ7wucQ5YfvgJWllQcFke3
TsLA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
h=user-agent:message-id:subject:to:from:date
:content-transfer-encoding:mime-version:dkim-signature;
bh=mi5OYCi9DQlbIlkaJu7GjAqOb0wjqh+rUszwxPLA9Go=;
b=DoS3qLtcrHQHoWrprfzE5x/voUxyWk4EhW8Ladw+bqQzaBJ7a2D9VAUrG5K/S+Oo4r
PswIXoWD1M33b7mHHDWvHXgbrT4nbTqO9hF4B647Q9cAM3QaI1EE0177vMu6IYIHTOms
Ypr/tRi5LNRzSLGq/pJtlSXac4C4ukn1yxr51cvxdFeWkg3Di1hHRLgsjIU8lR5ZARG4
dCpnun9iXM1wAqiC1ZnWxbjEbMKPpDS6X1Anhov0228BB1zlTdH0GpChhHCXmU6527/z
aGfBJDw31s2aAgzMeU4lH0oimuTl5rHpKWVNSLWvZcZvzgslBaTw5WML6SaNhdkAQikN
BcWw==
ARC-Authentication-Results: i=1; mx.google.com;
dkim=pass header.i=@mydomain.com header.s=default header.b=P4xZYZnS;
spf=pass (google.com: domain of admin@mydomain.com designates IP.MY.VPS.SERVER as permitted sender) smtp.mailfrom=admin@mydomain.com;
dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=mydomain.com
Return-Path: <admin@mydomain.com>
Received: from s1.mydomain.com (s1.mydomain.com. [IP.MY.VPS.SERVER])
by mx.google.com with ESMTPS id u12si4998068wrw.29.2019.06.15.08.01.59
for <account@gmail.com>
(version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
Sat, 15 Jun 2019 08:01:59 -0700 (PDT)
Received-SPF: pass (google.com: domain of admin@mydomain.com designates IP.MY.VPS.SERVER as permitted sender) client-ip=IP.MY.VPS.SERVER;
Authentication-Results: mx.google.com;
dkim=pass header.i=@mydomain.com header.s=default header.b=P4xZYZnS;
spf=pass (google.com: domain of admin@mydomain.com designates IP.MY.VPS.SERVER as permitted sender) smtp.mailfrom=admin@mydomain.com;
dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=mydomain.com
Received: from localhost (localhost [IPv6:::1]) by s1.mydomain.com (Postfix) with ESMTPA id 8A23E39C for <account@gmail.com>; Sat, 15 Jun 2019 17:01:58 +0200 (CEST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mydomain.com; s=default; t=1560610918; bh=mi5OYCi9DQlbIlkaJu7GjAqOb0wjqh+rUszwxPLA9Go=; h=Date:From:To:Subject; b=P4xZYZnScir+HqdQTRQc5sM7GrKSZ6Vn2A9zcFh5xbYv7JUPCtEv8QIZO7VA2e0o/
4q6Ilnn0PVX1R697f1sdoOzjr+KiuGbhizTNPYCSIo3Cc0TOleIAacNzU4Qirm11HY
xvXYXPCkzCQyB+sWX2/UaZKuJ+IinGWINXUhvzFg=
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII; format=flowed
Content-Transfer-Encoding: 7bit
Date: Sat, 15 Jun 2019 17:01:58 +0200
From: admin@mydomain.com
To: account@gmail.com
Subject: test
Message-ID: <589b3d7f40b9d06ad1f9c5e7e25532f6@mydomain.com>
X-Sender: admin@mydomain.com
User-Agent: Roundcube Webmail/1.3.8