バルクバウンス - スパマー？どのように？

さて、昨夜私のメールサーバー（postfix + dovecot + mysql）で「配信されていない」返送メールがたくさん発生し始めました。

私を混乱させることは、彼らが私のドメインをなりすましたが、私のメールホストだけを送ることができ、受信サーバーはそれを厳密にする必要があることを示すSPFレコードを設定したということです。

編集：私のSPFレコード -

example.org.       TXT  "v=spf1 a mx ptr -all"

100を超えるメッセージの一貫性のみが私のドメインです。

私の場合、すべてが大丈夫で、これらのバウンスは実際のバウンスであり、SPFレコードは実際に送信されたすべてのメッセージをなりすましとしてマークすると仮定する必要がありますか？

以下は電子メールの完全なヘッダーです。内部ホスト名をsrvr1ドメインに変更しましたexample.org。他のすべての名前/アドレスは本当です。面倒なことに、SPFレコードを設定しましたが、もともと受信サーバーはこのメッセージをスパムとしてマークしないようです。

これに提案がありますか？

Return-Path: <>
Delivered-To: [email protected]
Received: from mail.example.org
    by srvr1 (Dovecot) with LMTP id +m3lJVxxkVocZgAAa5pXxw
    for <[email protected]>; Sat, 24 Feb 2018 14:06:20 +0000
Received: by mail.example.org (Postfix)
    id 95F85462B3; Sat, 24 Feb 2018 14:06:20 +0000 (UTC)
Date: Sat, 24 Feb 2018 14:06:20 +0000 (UTC)
From: [email protected] (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: [email protected]
Auto-Submitted: auto-replied
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
    boundary="5CA7D462B1.1519481180/mail.example.org"
Content-Transfer-Encoding: 8bit
Message-Id: <[email protected]>

This is a MIME-encapsulated message.

--5CA7D462B1.1519481180/mail.example.org
Content-Description: Notification
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

This is the mail system at host mail.example.org.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<[email protected]>: host mx1.free.fr[212.27.48.6] said: 550 spam detected
    (in reply to end of DATA command)

--5CA7D462B1.1519481180/mail.example.org
Content-Description: Delivery report
Content-Type: message/delivery-status
Content-Transfer-Encoding: 8bit

Reporting-MTA: dns; mail.example.org
X-Postfix-Queue-ID: 5CA7D462B1
X-Postfix-Sender: rfc822; [email protected]
Arrival-Date: Sat, 24 Feb 2018 14:06:18 +0000 (UTC)

Final-Recipient: rfc822; [email protected]
Original-Recipient: rfc822;[email protected]
Action: failed
Status: 5.0.0
Remote-MTA: dns; mx1.free.fr
Diagnostic-Code: smtp; 550 spam detected

--5CA7D462B1.1519481180/mail.example.org
Content-Description: Undelivered Message
Content-Type: message/rfc822
Content-Transfer-Encoding: 8bit

Return-Path: <[email protected]>
Received: from sinovapaint.com (unknown [85.255.199.39])
    (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
    (No client certificate requested)
    by mail.example.org (Postfix) with ESMTPSA id 5CA7D462B1
    for <[email protected]>; Sat, 24 Feb 2018 14:06:18 +0000 (UTC)
Date: Sat, 24 Feb 2018 15:06:16 +0100
To: [email protected]
From: "Annabel A." <[email protected]>
Reply-To: "Annabel A." <[email protected]>
Subject: =?utf-8?Q?Y_a-t-il_d'autres_bons_=C3=A9talons_au_lit_=3F?=
Message-ID: <[email protected]>
X-Mailer: PHPMailer 5.2.23 (https://github.com/PHPMailer/PHPMailer)
MIME-Version: 1.0
Content-Type: multipart/alternative;
    boundary="b1_15f058ce5dc516426d9dc772f549682f"
Content-Transfer-Encoding: 8bit
X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,HTML_MESSAGE,
    URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.1
X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on srvr1