Finding Existing Plus Addresses

Exchange Online will automatically enable “Plus Addressing” for all tenants from Jan 2022. This change may cause issues if you have existing mailboxes where the SMTP address contains a + sign. That is, directors+managers@contoso.com would be considered a broken email address from Jan 2022 in Exchange Online. So you need to check you have no… Continue reading Finding Existing Plus Addresses

Outlook AutoDetect And Broken AutoDiscover

Those in the Exchange Server space for a number of years know all about AutoDiscover and the many ways it can be configured and misconfigured – if even configured at all. Often misconfiguration is to do with certificates or it is not configured at all because it involves certificates and I thought I was aware… Continue reading Outlook AutoDetect And Broken AutoDiscover

550 5.1.8 Access denied, bad outbound sender AS(42003)

“Your message couldn’t be delivered because you weren’t recognized as a valid sender. The most common reason for this is that your email address is suspected of sending spam and it’s no longer allowed to send email. Contact your email admin for assistance.” This is an error you get when your anti-spam “outbound” policy restricts… Continue reading 550 5.1.8 Access denied, bad outbound sender AS(42003)

[New] External Email Notification in Exchange Online

This is a new feature released in March 2021 that adds support in Outlook (Mac, OWA, Mobile) for the display of the external status of the sender – note at the time of writing it does not add this feature to Outlook for the PC. This should be used to replace the way this has… Continue reading [New] External Email Notification in Exchange Online

Azure AD Consent For Zoom App Not Applying

This is a issue where you enabled Admin Approved Consent in Azure AD (as you should) and you require apps that have high data access rights to be approved. The Zoom add-in/desktop app falls into this category as it requires write access to your calendar and your contacts in Exchange Online. But if you set… Continue reading Azure AD Consent For Zoom App Not Applying

Why Do Comments In Microsoft 365 Planner Disappear?

So first you need an Exchange Online mailbox for comments to work. Comments to the tasks of Plans are stored in the Microsoft 365 Group mailbox, and you need an Exchange Online mailbox to access the M365 Group mailbox. Behind the scenes, or actually not that behind the scenes, the process for comments is as… Continue reading Why Do Comments In Microsoft 365 Planner Disappear?

Exchange Online Warning On Receipt Of New Email Sender

First Contact Safety Tip

Released recently to no fanfare at all, Microsoft now has a SafetyTip that appears if you receive email from a first time recipient. Most often phish emails will come from an address you have never received email from before, and sometimes this email will try to impersonate people you communicate with or are internal to… Continue reading Exchange Online Warning On Receipt Of New Email Sender

Microsoft 365 From A Raspberry Pi 400 Personal Computer

So my new computer arrived today, its a keyboard and a few cables, and as my first computer was a ZX Spectrum when I was 14, this brings back a few memories. But, is it usable today with services such as Microsoft 365? Lets see… First, the actual computer is in the keyboard, but its… Continue reading Microsoft 365 From A Raspberry Pi 400 Personal Computer

Enabling Better Mail Flow Security for Exchange Online

At Microsoft Ignite 2020, Microsoft announced support for MTA-STS, or Mail Transfer Agent Strict Transport Security. This is covered in RFC 8461 and it includes making TLS for mail flow to your domains mandatory whereas it is currently down to the decision of the sender. You can publish your SMTP endpoint and offer the STARTTLS… Continue reading Enabling Better Mail Flow Security for Exchange Online

Reporting on MTA-STS Failures

This article is a follow up to the Enabling Better Mail Flow Security for Exchange Online which discusses setting up MTA-STS and in this article we cover the reporting for MTA-STS. To get daily reports from each sending infrastructure to receive reports on MTA-STS you just create a DNS record in the following format: It… Continue reading Reporting on MTA-STS Failures

Enable EOP Enhanced Filtering for Mimecast Users

Email

Blog post updated March 2020 to include more specific IP ranges for all Mimecast regions and to fix an issue where the email sender is also using the same Mimecast region as yourself and the risk of SPF failures. Enhanced Filtering is a feature of Exchange Online Protection (EOP) that allows EOP to skip back… Continue reading Enable EOP Enhanced Filtering for Mimecast Users

Mail Flow To The Correct Exchange Online Connector

In a multi-forest Exchange Server/Exchange Online (single tenant) configuration, you are likely to have multiple inbound connectors to receive email from the different on-premises environments. There are scenarios where it is important to ensure that the correct connector is used for the inbound message rather than any of your connectors. Here is one such example.… Continue reading Mail Flow To The Correct Exchange Online Connector

Force Mailbox Migration With Bad Items To Complete (2020)

It used to be easy to complete an Exchange Server > Exchange Online move request that had bad items, but this has changed recently. In the last short while Move Requests (and Migration Batches) have begun to include a property called DataConsistencyScore If the result from the above is “Investigate” then you will not be… Continue reading Force Mailbox Migration With Bad Items To Complete (2020)

Making Your Office 365 Meeting Rooms Accessible

Or How to Use Set-Place to Configure Your Meeting Rooms or How Wheelchair Users Can Find The Best Meeting Rooms In Your Organization etc. – there are many different titles I can think of for this blog post. They are all to do with setting useful properties against your meeting rooms so that your users… Continue reading Making Your Office 365 Meeting Rooms Accessible

Review and Audit Offensive Language in Office 365 Communications

A new feature as of May 2018 in Office 365 is to filter communications based upon the offensive language machine learning filter. This is part of the Supervision settings that have been available for a number of years. The Offensive Language model uses a combination of machine learning, artificial intelligence, and keywords to identify inappropriate… Continue reading Review and Audit Offensive Language in Office 365 Communications