==== Required information ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
======== Required information ====
- iRedMail version - 0.9.5-1
- Linux/BSD distribution name and version - Ubuntu server 14.04.5 LTS
- Store mail accounts in which backend - mySQL
- Web server- Apache/2.4.7
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I apologize in advance for this lengthy error message.

Diagnostic information for administrators:

Generating server: VE1EUR01HT041.mail.protection.outlook.com

sender@domain.tld
mailserver.domain.tld
Remote Server returned '554 5.7.1 <sender@domain.tld>: Recipient address rejected: Policy rejection not logged in'

Original message headers:

Received: from VE1EUR01FT034.eop-EUR01.prod.protection.outlook.com
(10.152.2.56) by VE1EUR01HT041.eop-EUR01.prod.protection.outlook.com
(10.152.3.59) with Microsoft SMTP Server (version=TLS1_2,
cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.1101.12; Thu, 1
Jun 2017 21:28:50 +0000
Received: from AM5P193MB0211.EURP193.PROD.OUTLOOK.COM (10.152.2.54) by
VE1EUR01FT034.mail.protection.outlook.com (10.152.2.235) with Microsoft SMTP
Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id
15.1.1101.12 via Frontend Transport; Thu, 1 Jun 2017 21:28:50 +0000
Received: from AM5P193MB0211.EURP193.PROD.OUTLOOK.COM ([::1]) by
AM5P193MB0211.EURP193.PROD.OUTLOOK.COM ([fe80::9ca1:865a:1e4f:9ec%14]) with
Microsoft SMTP Server id 15.01.1124.020; Thu, 1 Jun 2017 21:28:50 +0000
From: =?utf-8?B?Sm9uYXRoYW4gU8OpbGVh?= <sender@domain.tld>
To: "****@live.se" <****@live.se>
Subject: tetw
Thread-Topic: tetw
Thread-Index: AQHS2x4PFjYmi11njUKwBvjeHzmeEw==
Date: Thu, 1 Jun 2017 21:28:41 +0000
Message-ID: <783adfba-0052-c074-3ade-0a619be74578@domain.tld>
Content-Language: en-US
X-MS-Has-Attach:
X-MS-Exchange-Inbox-Rules-Loop: ****@live.se
X-MS-TNEF-Correlator:
authentication-results: mailserver.domain.tld (amavisd-new);    dkim=pass (2048-bit
key) reason="pass (just generated, assumed good)"    header.d=domain.tld
received-spf: Pass (protection.outlook.com: domain of domain.tld designates
45.76.1.225 as permitted sender) receiver=protection.outlook.com;
client-ip=45.76.1.225; helo= mailserver.domain.tld;
x-incomingtopheadermarker: OriginalChecksum:B9CF5E5350B9C40E31D9CE1E9C6B9DD9CA130817007F60DD1A0081DADAF58F61;UpperCasedChecksum:750084409E55541A44391DB021FF8858DAC274917F2152F5AFF073B165764DAB;SizeAsReceived:2231;Count:19
dkim-signature: v=1; a=rsa-sha256; c=relaxed/simple; d=domain.tld; h=
    content-language:content-transfer-encoding:content-type
    :content-type:mime-version:user-agent:date:date:message-id
    :subject:subject:from:from:to; s=dkim; t=1496352526; x=    1497216527;
bh=ukcfGO5DgNagzVZwxNVpBaXamxinNjQIdhSM9Bf8N/8=; b=B
    Z6HymDbRmA9Yton+pGAPxKLQUjdmFCFMRCJZ/sfVGwGCfyn+qVY+zMom6brrHBDM
    6pYE4LNgGHkVT83PBN+8rZKVWSL4SxJEAV5HKI2/9cJONO4dwHMJPazFjvgOxgfk
    kSf+uGOFHxPmm+FZYLFBi9Y1aORcKW+NHFl0MknrcAh0gnbbp9fniaf+BPm+O0uD
    c/onRliEOs4M7X8q8WRRVcUPWTaCDwKQMjsclH5zn8rXK3tMCQwDkJyh6uf3Xzol
    RBVE7set/a46Ez6WLKOCjhR3dozohZycWILZmaPauYySs3jAWRz5BfOb0glch7AO
    6sMskJHAmKljoO8PdSCUA==
x-virus-scanned: Debian amavisd-new at mailserver.domain.tld
user-agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101
Thunderbird/52.1.1
x-originalarrivaltime: 01 Jun 2017 21:28:47.0282 (UTC)
FILETIME=[0DB7D920:01D2DB1E]
x-incomingheadercount: 64
x-eopattributedmessage: 1
x-eoptenantattributedmessage: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa:0
cmm-sender-ip: 45.76.1.225
cmm-sending-ip: 45.76.1.225
cmm-authentication-results: hotmail.com; spf=pass (sender IP is 45.76.1.225;
identity alignment result is pass and alignment mode is relaxed)
smtp.mailfrom=sender@domain.tld; dkim=pass (identity alignment result is pass
and alignment mode is relaxed) header.d=domain.tld; x-hmca=pass
header.id=sender@domain.tld
cmm-x-sid-pra: sender@domain.tld
cmm-x-auth-result: PASS
cmm-x-sid-result: PASS
cmm-x-message-status: n:n
cmm-x-message-delivery: Vj0xLjE7dXM9MDtsPTA7YT0wO0Q9MjtHRD0yO1NDTD02
cmm-x-message-info: 11chDOWqoTkwga12SxgHsROii5h1XNueOWnfa9ZdbSNcl/mJQJoiWKgRAnWs/tqoYYCA2oRP/bP3kSsekpe/1X5iEHAk77t1R79sgPUe14ecr/8VGyoLAJPYP0l+F7wMfavJVUUWAiq5P53DPGXdvBwrwOuHoi2mmn0rJVLyMEqQ6e6NRd37ezgKInNjpHnN5VsBwemgx4DWdeNsdnuk5Vs0q0E/0HhVwOpwmCV7ZRZeFxSx/h8+Hg==
x-microsoft-exchange-diagnostics:
    1;VE1EUR01HT041;5:d30PlfKDNvMWXsuhVsuQ/rlHWh6AMjE95RneyBQP9QT7HVe9+cL6331j2QvPh+v68FkOG/x+8mHaJKPYiJOpC/ylL7v6UTljk0IKYQOxP9NCUdlx4hfd2XqLlgxx2PsnPwKWWn5hYmSQvvfO5rvMsFkEcRUtHa36yRATFqaB+crOyXqdy6JKKsbwK4frAxWwxqpw6MxuowtfaTSuWQ1Jl6ew2QmfbTZVwK1E3oGog1y4s7j8hb31GfqeRLRzh8mPVQT1S8yc0HleHztDrOZWbth5AIhlu9I6znfO+ff86NPTgxH62JxMknI4wY2dhMDUtjtELpIM4ZDqUNMn5Ytacv485zfdx2UMQHcso1SHl9M9UZO89cP+O4HVy1L2VCG7+52Z676lKgkqJELXCZcNrw0e7vytpIerkM4BadW+LOOV9vtAZij9GR0FrfVaZXwSMSbNVYtQh8Dt+hzrmdKzlri6S42Fn6ax2ICY6Y3+yHYkxefrsxZTjIcq7Ir4QvmT;24:QPCw6SmQyJVjPSMziQwtXOt1G3O8HEzn4P8SAnz8aNVSkwa7tESShAyy/vaJ481C1M9nTr9zWAl5SEgfn+NObS+ecSkqQAtnVc/P4cHmkII=;7:lVpi+HU3HajHEQ1I6nZrk0I/1//YrxyYdZQnFqbnbbuqPyBterBO6Gp/bQ43/WrWq5+PHIZTz7r0UCWaJ/VKLPj5t2aqbpQdjBL82TCpg8Usam6b/lqAsSbk1MUz+A4HXa5kpkAqwzBopXF4N04kgaSjZUi9c7XJRvT6wklNKdsvrKJgMEAHU8A3dkbatl6JR8zudnDaxSEwwh3KIFs9Xhp8c1RZPX9Yl3edDpi4jbUH4IUUy6Xn3PyNVhlvJgUMfGhaS9A5jNHJuGIPCVWmWgulrOM46Jim13uhOxFRyVSTVXwQSUN6CEsCoirXplAk
x-forefront-antispam-report: EFV:NLI;SFV:NSPM;SFS:(7070007)(98901004);DIR:OUT;SFP:1901;SCL:1;SRVR:VE1EUR01HT041;H:AM5P193MB0211.EURP193.PROD.OUTLOOK.COM;FPR:;SPF:None;LANG:en;
x-ms-publictraffictype: Email
x-ms-traffictypediagnostic: VE1EUR01HT033:|VE1EUR01HT041:
x-ms-office365-filtering-correlation-id: e8f1c9b7-df80-454b-6c74-08d4a9353228
x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017031320274)(201702221075);SRVR:VE1EUR01HT041;
x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(444000031);SRVR:VE1EUR01HT033;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:VE1EUR01HT033;BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(444000031);SRVR:VE1EUR01HT041;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:VE1EUR01HT041;
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
x-ms-exchange-crosstenant-originalarrivaltime: 01 Jun 2017 21:28:48.7637 (UTC)
x-ms-exchange-crosstenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa
x-ms-exchange-crosstenant-fromentityheader: Internet
x-ms-exchange-transport-crosstenantheadersstamped: VE1EUR01HT033
x-ms-exchange-transport-endtoendlatency: 00:00:01.5347627
Resent-From: <****@live.se>
x-microsoft-exchange-diagnostics-untrusted: 1;VE1EUR01HT033;7:8Dw/Sofk6CCBaLge/PJl3Gt7V08jm8cCZAwV6TG7pjCzChrFxXhtKwRCFmM1a7yJ6aW5ueh8TJ7NLwhIw8qU5MpkOwBsF5EanwfI8+25NUuCu/SqtO9yaJOOfLzNY7oMR9YOcGTklfguA4hfehlYuLxAD8aP6lPC/y8Rp+u/qkDt533eVWUmHQ5Lnbon9SAYRWIVAqhV7aIhRVavziFKVqOMf9onBw6duPAnIbcN/tNGT1lec3TNX+4tje8RLhXv077joJGQUyfs76YoP47p7e+CzJfEgFlWykyVph7TZkuIjlh3INWA5958Rh7pTuTh9zkCkN1Dz+EOtzu+4K7+bA==
x-forefront-antispam-report-untrusted: EFV:NLI;SFV:SPM;SFS:(28900001);DIR:INB;SFP:;SCL:5;SRVR:VE1EUR01HT033;H:SNT004-MC4F28.hotmail.com;FPR:;SPF:None;LANG:en;
x-microsoft-antispam-untrusted: BCL:0;PCL:0;RULEID:(23075)(22001)(8291500097)(8291501071);SRVR:VE1EUR01HT033;
x-ms-exchange-transport-crosstenantheadersstripped: VE1EUR01FT034.eop-EUR01.prod.protection.outlook.com
x-forefront-prvs: 0325F6C77B
Content-Type: text/plain; charset="utf-8"
Content-ID: <D064D6743DBA604E9F4D4F340FBBA932@EURP193.PROD.OUTLOOK.COM>
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-OriginatorOrg: outlook.com
X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Jun 2017 21:28:50.5172
(UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Internet
X-MS-Exchange-CrossTenant-id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VE1EUR01HT041

I am having strange issues with sending emails to email addresses located at Microsoft (outlook.com, live.com. office 365 etc)
According to this thread:
http://www.iredmail.org/forum/topic9719 … ction.html

It should be fixed by deactivating "reject_null_sender", in my case it does not work.