This report relates to a message you sent with the following header fields:
Message-id: <2e7079da62d02cda7451f9e72825ea4d@qq.com>
Date: Thu, 10 Jan 2019 01:04:47 +0800
From: =?utf-8?B?6JSa6ZOt5ZW4?= <752989663@qq.com>
To: biemh@bec.eu
Subject: 752989663
Your message cannot be delivered to the following recipients:
Recipient address: biemh@bec.eu
Reason: SMTP transmission failure has occurred
Diagnostic code: smtp;554 5.7.1 Mail from this email address is not allowed and has been blocked.(no.25 pattern matched)
Remote system: dns;mail.bec.euskaltel.es (BECCORREO.bec.eu Microsoft ESMTP MAIL Service ready at Wed, 9 Jan 2019