My registration emails are going into GMail spam folders. How can I prevent that? I already added DKIM to allow delivery. Here are example headers for the registration email.
Delivered-To: email@example.com
Received: by 2002:a05:6504:3d7:0:0:0:0 with SMTP id b23csp6053738ltp;
Wed, 30 Jan 2019 11:09:15 -0800 (PST)
X-Google-Smtp-Source: ALg8bN6fQ+qqhTFRV5Qr/q70s9IFosZvesG7Dmzk5AZalWFB4Zi4fUsQJ00Md+r1/r9iPBDXA0DM
X-Received: by 2002:a0c:df12:: with SMTP id g18mr28982477qvl.208.1548875355040;
Wed, 30 Jan 2019 11:09:15 -0800 (PST)
ARC-Seal: i=1; a=rsa-sha256; t=1548875355; cv=none;
d=google.com; s=arc-20160816;
b=yP9dOFjSIRTYU+LqhCX56Xd8/10J9989fEQ9ql5dJP3ceWdaaLuL3GYDHjG4Sa9QHq
wqiJdYKM2Ujl1Lvv8TNbGer+4bR/lqSzeXG6id7Bl3VuFZGmrtNtTSPtnWKOc6z/OY/+
3Zt1XhKKFr9CGFHab+jaWtM1ltv4WoeDqpIAhi0BtW3foMhyU0WD48wNWy1X4NlnSypd
BiNgVh7GkNl/8DCjlf6V/BxbH34ASK3X37kmfdX2UVQvjr1HJZvEZVy+EyuiGIjZ/xto
/n3HJOySDqwnGCeLq4glO/scK4BCH4hUfIpGFzmQvW8Gh3j2VpnNhRenvxVM52nWxUvh
6NjA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
h=date:message-id:reply-to:from:subject:to:dkim-signature:dkim-filter;
bh=kEZIXhUomBN4crsYGUyhYohOLyjNevvGQ0TDVma1FHc=;
b=gmsjTgwm4XENTrSSq5ldpupgtGd1RRQMHMnZZXe6ZB1CWl4pNu0RUyskfq+LCXkcXR
gkUfgxalJzXa905LfixK/svK+7MDR66UpcurWqLdjjywSaccQ3sXivKJtF0csKVH6mio
3mB76+08diga4O06pgPife7j2ZrvKgWDT/h3Cpul/IbnXhLdNQtp8FSrqzZQJOZO9De/
TXYJl47wNVvT2RZjFxGLsl0vvsbCkB0Z8eez0dDHtM0KaXAOTPFhCU4SjfNuIutEloqT
ErXShhUywZkzH+CcpfMUutlznRXmXDFUrxWksXwRFq2Ph43GmYujeQUBBOnCCmThQ284
VfoA==
ARC-Authentication-Results: i=1; mx.google.com;
dkim=pass header.i=@fsphub.org header.s=default header.b=K3KkwT0X;
spf=pass (google.com: best guess record for domain of apache@fsphub.org designates 68.183.51.228 as permitted sender) smtp.mailfrom=apache@fsphub.org
Return-Path: <apache@fsphub.org>
Received: from fsphub.org (fsphub.org. [68.183.51.228])
by mx.google.com with ESMTP id x2si256188qta.285.2019.01.30.11.09.14
for <email@example.com>;
Wed, 30 Jan 2019 11:09:14 -0800 (PST)
Received-SPF: pass (google.com: best guess record for domain of apache@fsphub.org designates 68.183.51.228 as permitted sender) client-ip=68.183.51.228;
Authentication-Results: mx.google.com;
dkim=pass header.i=@fsphub.org header.s=default header.b=K3KkwT0X;
spf=pass (google.com: best guess record for domain of apache@fsphub.org designates 68.183.51.228 as permitted sender) smtp.mailfrom=apache@fsphub.org
Received: by fsphub.org (Postfix, from userid 48)
id 4684D469721; Wed, 30 Jan 2019 19:09:14 +0000 (UTC)
DKIM-Filter: OpenDKIM Filter v2.11.0 fsphub.org 4684D469721
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=fsphub.org;
s=default; t=1548875354;
bh=tqPfB5fgzqdYB//LkPLwsKL0uhY6BA+sfPDP0I/KpZc=;
h=To:Subject:From:Reply-To:Date:From;
b=K3KkwT0Xa9qv0vjM1p2rLQuUqVJLbCYWFAnsAuCegPu++c+LCWRJWfKLH4ejHX9qr
3l1fP7pS0LkPa0DU+AzFacIHQr5hfDl2tYbRe4mwMoHAQ4PoZUYD8rATjtbS0SNA30
fUjGl3Do55wOdK0M8hlbC299hM/uQIkT5IyC7quQ=
To: email@example.com
Subject: Registration confirmation for FSP Hub
X-PHP-Originating-Script: 0:network.php
From: Hubzilla <Administrator@fsphub.org>
Reply-To: Hubzilla <noreply@fsphub.org>
Content-Type: text/plain; charset=UTF-8
Message-Id: <20190130190914.4684D469721@fsphub.org>
Date: Wed, 30 Jan 2019 19:09:14 +0000 (UTC)