trying to forward emails external using Exchange 2013 on Prem. Sophos Central Email setup.
All emails come in and go out as normal, just Forwarding fails
External emails sent to me from internal and external users are not being forwarded on to an external account:
Mail delivery to following recipients failed: email@example.com - 550 5.7.1 Command rejected
Resent-From: <User1@domain1.com>Received: from Exchange (10.) by exchange (10.) with Microsoft SMTP Server (TLS) id 15.0.847.32; Thu, 7 Apr 2022 12:42:47 +0100Received: from inbound-18-216-7-10-us-east-2.prod.hydra.sophos.com(220.127.116.11) by Exchange.domain1 (IP) with Microsoft SMTP Server id 15.0.847.32 via Frontend Transport; Thu, 7 Apr 2022 12:42:28+0100Received: from ip-172-21-100-31.us-east-2.compute.internal(ip-172-21-100-31.us-east-2.compute.internal [127.0.0.1]) byinbound-18-216-7-10-us-east-2.prod.hydra.sophos.com (Postfix) with ESMTP id4KZ00l6CnfzPjdl for <User1@domain1.com>; Thu, 7 Apr 2022 11:44:39+0000 (UTC)Authentication-Results: mx-01-us-east-2.prod.hydra.sophos.com;spf=pass firstname.lastname@example.org;dkim=pass header.d=domain3 header.from=domain3; dmarc=pass (recordpolicy=quarantine) header.from=domain3Received-SPF: pass receiver=mx-01-us-east-2.prod.hydra.sophos.com;client-ip=18.104.22.168; envelope-from=< email@example.com >;helo=GBR01-LO2-obe.outbound.protection.outlook.com;X-Sophos-Product-Type: GatewayX-Sophos-Email-ID: c65874521353416d8dbc3e35fd16a1a1Received: from GBR01-LO2-obe.outbound.protection.outlook.com(mail-lo2gbr01on2084.outbound.protection.outlook.com [22.214.171.124]) (usingTLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx-01-us-east-2.prod.hydra.sophos.com (Postfix) with ESMTPS id 4KZ00c6Rhsz9rwG for <firstname.lastname@example.org>; Thu, 7 Apr
I have seen similar discussions on here, but no answers.
any help appreciated.