Gfrktyl

I've configured a Postfix + Dovecot email server. I took care of SPF, DKIM, DMARC and added appropriate headers to the message. I haven't used the machine for 2 years, so it can't be blacklisted from previous users. For reasons unknown to me, my email still gets marked as spam by gmail. This is the source of the mail, as seen by gmail client. I stripped away some of the very long unique ids and IPs, to make it more readable.

Delivered-To: targetemailaddress@gmail.com

Received: by IPv6_here with SMTP id s12csp565193ios;

        Fri, 1 Feb 2019 07:45:41 -0800 (PST)

X-Google-Smtp-Source: someuniquestring

X-Received: by 2002:a63:6c48:: with SMTP id h69mr34585542pgc.139.1549035941764;

        Fri, 01 Feb 2019 07:45:41 -0800 (PST)

ARC-Seal: i=1; a=rsa-sha256; t=1549035941; cv=none;

        d=google.com; s=arc-20160816;

        b=verylongstringhere==

ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;

        h=date:message-id:content-transfer-encoding:mime-version:reply-to

         :from:sender:subject:to:dkim-signature:dkim-filter;

        bh=somelongstring=;

        b=verylongstringhere2==

ARC-Authentication-Results: i=1; mx.google.com;

       dkim=pass header.i=@mycustomdomain.com header.s=201901 header.b=qCd3nM9G;

       spf=pass (google.com: domain of support@mycustomdomain.com designates IPv6_here_2 as permitted sender) smtp.mailfrom=support@mycustomdomain.com;

       dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=mycustomdomain.com

Return-Path: <support@mycustomdomain.com>

Received: from mycustomdomain.com (mycustomdomain.com. [IPv6_here_2])

        by mx.google.com with ESMTPS id k91si7726103pld.283.2019.02.01.07.45.41

        for <targetemailaddress@gmail.com>

        (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);

        Fri, 01 Feb 2019 07:45:41 -0800 (PST)

Received-SPF: pass (google.com: domain of support@mycustomdomain.com designates IPv6_here_2 as permitted sender) client-ip=IPv6_here_2;

Authentication-Results: mx.google.com;

       dkim=pass header.i=@mycustomdomain.com header.s=201901 header.b=qCd3nM9G;

       spf=pass (google.com: domain of support@mycustomdomain.com designates IPv6_here_2 as permitted sender) smtp.mailfrom=support@mycustomdomain.com;

       dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=mycustomdomain.com

Received: by mycustomdomain.com (Postfix, from userid 48)

    id 743B95C468; Fri,  1 Feb 2019 16:46:12 +0100 (CET)

DKIM-Filter: OpenDKIM Filter v2.11.0 mycustomdomain.com 743B95C468

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mycustomdomain.com;

    s=201901; t=1549035972;

    bh=somelongstring=;

    h=To:Subject:From:Reply-To:Date:From;

    b=vverylongstringhere3==

To: targetemailaddress@gmail.com

Subject: Update on the files

Sender: Support Team <support@mycustomdomain.com>

From: Support Team <support@mycustomdomain.com>

Reply-To: Support Team <support@mycustomdomain.com>

MIME-Version: 1.0

Content-Type: text/plain; charset=us-ascii

Content-Transfer-Encoding: quoted-printable

Message-Id: <20190201154612.743B95C468@mycustomdomain.com>

Date: Fri,  1 Feb 2019 16:46:12 +0100 (CET)



You start as a beginner and then you make it to the end.

I strongly feel that my problem has to do with inadequate headers. What headers should I add or change? I am not sure what else should I do..

Looking at that email, Id imagine Giogle us objecting to the content - as a mail admin that looks spammy to me

 * Generic from

 * Generic subject with bad Englush Grammer

 * Short content with generic text and bag grammer

 * Subject line talks about file (trying to trick you into installing malware?)

It is unclear if this is a new domain, but sending stuff from a new domain is also more likely to be spam.