Sender Rewriting Scheme (SRS) coming to Office 365

The introduction of email authentication mechanisms like SPF, DKIM, and DMARC have improved email security and spoofing prevention. However, some scenarios have been disrupted by these authentication mechanisms, namely auto-forwarding and relaying. Here in Office 365, we are committed to ensuring the security of our customers and the general integrity of the email ecosystem that…


Best practices for using assigned Office 365 DNS records

As someone who reads through hundreds of support cases each month, nothing pains me more than seeing customers struggling with seemingly complex issues, only to discover that the root cause is quite simple. Never is this truer than it is with DNS. Some of the most complicated security and lost mail issues boil down to…


Mail flow insights are available in Security & Compliance center

Update 6/22/18: for more updates on the subject, please see this post. We’re excited to announce that Mail flow Insights will soon be available in the Office 365 Security & Compliance Center. We’ll continue to create and refine mail flow insights to help improve productivity for admins, and we’ll announce them as they become available….


New Message Trace in Office 365 Security & Compliance Center

Overview Message Trace is a key tool for email admins to troubleshoot and track the health of their organization’s mail flow. Message Trace in the Exchange Admin Center (EAC) is a useful tool for tracing messages, but it’s visually cluttered and confusing, and it lacks a number of more sophisticated capabilities. To make Message Trace…


New date for discontinuation of support for Session Border Controllers in Exchange Online Unified Messaging

Update 9/12/2018: We have two important updates for customers: As we prepare to discontinue support for PBX’s connecting to Exchange Online Unified Messaging, we will remove the ability for tenant admins to configure new PBX connections on or after October 8, 2018. Existing connections will not be impacted by this change. Based on customer feedback,…


Announcing the increase of the Public Folder limit in Exchange Online from 250,000 to 500,000 folders

Last September, we officially announced the increase of the supported limit of Public Folders in Exchange Online from 100,000 to 250,000. In line with our efforts to scale Public Folders even further, we are glad to announce that Exchange Online now officially supports public folder hierarchies of up to 500K public folders in the cloud…


Changes coming to the SMTP Authenticated Submission client protocol

There are a number of client protocols offered by Exchange Online to allow email clients to send email from their mailboxes. One of the most widespread protocols is SMTP Authenticated Submission (also known as SMTP Client Submission) which is supported by most email service providers. This non-proprietary protocol is used to send email by legacy…


OffCAT’s replacement – Microsoft Support and Recovery Assistant (SaRA)

After over five years of providing configuration information and solutions to known issues, the OffCAT team is planning to remove OffCAT from the Microsoft Download Center on May 31, 2018. The good news is that core OffCAT features have been consolidated with the Microsoft Support and Recovery Assistant for Office 365 (SaRA) tool at https://diagnostics.outlook.com/….


Office 365: Auto-Expanding Archives FAQ

In recent months we’ve been receiving quite a few questions from customers regarding auto-expanding archives. I’d like to clear up some of the misconceptions and answer some of the most frequently asked questions we get on this subject. Think of this as a FAQ on the subject. Before we get going, I strongly advise folks…


Demystifying Hybrid Free/Busy: Finding errors and troubleshooting

In this second part of the Demystifying Hybrid Free/Busy, we will cover troubleshooting of Hybrid Free/Busy scenarios, more specifically – how and where to find an actual error that will indicate where the problem is. Before venturing forth, please make sure that you have seen Part 1 of this demystifying series! Here is the graphics…