Trouble Receiving Emails from Microsoft Exchange - email

Question

When people try and send me emails from Microsoft Exchange, they get this error. I don't really deal with email servers and I have no idea where to start though. Is this problem our side or their side? Or how would I go about fixing this issue?
Delivery has failed to these recipients or groups:
'email#example.com' (email#example.com)
The server has tried to deliver this message, without success, and has stopped trying. Please try sending this message again. If the problem continues, contact your helpdesk.
Diagnostic information for administrators:
Generating server: company.com
email#example.com
Remote Server returned '550 4.4.7 QUEUE.Expired; message expired'
Original message headers:
Received: from company.com (10.0.0.9) by
company.com (10.0.0.9) with Microsoft SMTP Server (TLS) id
15.0.913.22; Mon, 16 Mar 2015 09:31:06 -0700
Received: from company.com ([fe80::795b:ac34:abcd:4825]) by
company.com ([fe80::795b:ac34:abcd:4825%12]) with mapi id
15.00.0913.011; Mon, 16 Mar 2015 09:31:06 -0700
From: John Doe
To: "'email#example.com'"
Subject: Any Random Subject
Thread-Topic: Any Random Subject
Thread-Index: AdBgBpfb1zC+ceABSy6pPCro6aJlsA==
Date: Mon, 16 Mar 2015 16:31:05 +0000
Message-ID:
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
x-vipre-scanned: 005461CE0096480054631B
x-originating-ip: [10.0.0.138]
Content-Type: multipart/mixed;
boundary="_004_d0873b00554f4a82a311cf02472b1080WCEX1wilcoxconstruction_"
MIME-Version: 1.0

Answer 1

Your key text is
"Remote Server returned '550 4.4.7 QUEUE.Expired; message expired'"
Try goggling on the "message expired" to help determine the exact cause.
https://social.technet.microsoft.com/Forums/exchange/en-US/00e9468e-84c8-43f9-9bfd-95a71320f15b/550-447-queueexpired-message-expired-?forum=exchangesvrgenerallegacy