I need Help

Question

i have issue when i send mails from my office 365 mail its not working here is the problem 

Delivery has failed to these recipients or groups:

s****************@hotmail.com (s****************@hotmail.com)

Your message wasn't delivered because the recipient's email provider rejected it.

Diagnostic information for administrators:

Generating server: DB4PR04MB0576.eurprd04.prod.outlook.com

s***********@hotmail.com

Remote Server returned '550 5.7.501 Service unavailable, Client host blocked using Spamhaus. To request removal from this list see http://www.spamhaus.org/lookup.lasso (AS16042849)'

Original message headers:

Authentication-Results: hotmail.com; dkim=none (message not signed)
 header.d=none;hotmail.com; dmarc=none action=none header.from=hyperuncle.com;
Received: from DB4PR04MB313.eurprd04.prod.outlook.com (*********) by
 DB4PR04MB0576.eurprd04.prod.outlook.com (1********1) with Microsoft SMTP
 Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id
 1******; Wed, 16 May 2018 17:57:11 +0000
Received: from DB4PR04MB313.eurprd04.prod.outlook.com
 ([fe80::9807:dc3c:b359:ca1a]) by DB4PR04MB313.eurprd04.prod.outlook.com
 ([fe80::9807:dc3c:b359:ca1a%17]) with mapi id *********; Wed, 16 May
 2018 17:57:11 +0000
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: binary

Answer 1

Hi Omar,

Based on the error message client host has been blocked using Spamhaus.

Therefore, I would suggest you please refer to the article under Third-party block list using the Spamhaus Delisting portal site for request removal and further assistance. See under Third-party block lists

Your understanding will be highly appreciated.

Best regards,

Shyamal