Article ID: 2618599 - View products that this article applies to.
Consider the following scenario in Microsoft Office 365 dedicated:
In this scenario, some members of the distribution group may not receive the email message. Additionally, you do not receive a non-delivery report (NDR).
This issue occurs because some email servers do not accept email messages that do not specify a return path. This behavior is a method of spam prevention. For example, consider the following example Simple Mail Transfer Protocol (SMTP) conversation:
Server: 220 smtp.contoso.com ESMTP Postfix
Client: HELLO relay.example.org
Server: 250 Hello relay.example.org, I am glad to meet you
Client: MAIL FROM: <>
Server: 250 Ok
Client: RCPT TO: firstname.lastname@example.org
In this example, the recipient server rejects the email message because the message does not have a return path.
Most frequently, the email message does not have a return path if both the ReportToManager and ReportToOriginator distribution group attributes are set to False, as follows:
To resolve this issue, set the Return-Path value to one of the following values:
To make this setting, set one of these attributes to True on the on-premises object (depending on the desired behavior), and allow for MMSSPP replication to the Microsoft Exchange Online environment.
Article ID: 2618599 - Last Review: November 26, 2014 - Revision: 7.0