Exchange Online Moves to Tighten Platform Security

Exchange Online announced two important changes on April 15. SMTP AUTH is being depreciated and a new external recipient rate limit is being introduced. The changes are intended to improve the security of Exchange Online. The introduction of an external recipient rate limit is also intended to reduce the ability of spammers to abuse the platform.

Running Exchange Online Historical Message Traces for Sets of Mailboxes

A question was asked about the best way to find out if shared mailboxes received email from certain domains over the past 60 days. Exchange Online historical message traces can extract trace data to allow us to check, but the process of running the message trace and then analyzing the data is just a little disconnected.

No Way Back to Exchange Server for Auto-Expanding Archives

Microsoft is introducing a block to stop customers attempting to move auto-expanding archives to Exchange Server. No very of the on-premises server has ever supported auto-expanding archives, so it’s reasonable to have a block. It’s still possible to move a primary mailbox back to Exchange Server, but its auto-expanding archive must stay in the cloud. It’s a good factor to take into account if an organization plans to use auto-expanding archives in the future.

Comparing Shared and Inactive Mailboxes

Exchange Online tenants have a choice between inactive mailboxes and shared mailboxes when the need arises to keep “leaver” data like that belonging to ex-employees. Inactive mailboxes are essentially a compliance tool and sometimes shared mailboxes are better choices. We explore both in this short article.

Countdown Accelerating to the Big Basic Authentication Turnoff

October 1, 2022, is when Microsoft begins the final process of removing support for basic authentication for 7 email connection protocols from Exchange Online. The process will take several months to complete, and when it’s done, Office 365 will be a safer place that attackers will find more difficult to penetrate. But it’s time for tenants to prepare, if you haven’t already done so, and we highlight some critical points from Microsoft’s most recent post on this topic.

Microsoft Gives Tenants Opt-Out for Exchange Online Plus Addressing

Microsoft intends to make the Exchange Online plus addressing feature available by default to all Microsoft 365 tenants after April 17, 2022. If you don’t want this to happen, you need to update the Exchange Online organization configuration to update the DisablePlusAddressInRecipients setting to True. After the opt-out 30-day period finishes, Microsoft will proceed with the deployment, so don’t say you weren’t warned!

Why Exchange Online Mailboxes have SharePoint Online Proxy Addresses

A post by the Exchange development group tried to explain why mailboxes have SharePoint Online proxy addresses. It’s all down to the Microsoft 365 substrate, which needs the proxy addresses to ingest digital twins from SharePoint Online into Exchange Online for use by shared services like Microsoft Search. The upshot is that you can’t remove a mailbox permanently without some background processes kicking in to make sure that SharePoint is taken care of.

Why Microsoft Reannounced the Send from Email Aliases Feature

Microsoft announced the preview of the Send from Email Aliases feature on January 25. The only problem is that the same feature was released in April 2021. And OWA gained full support for it in October 2021. So why would Microsoft reissue an existing feature? They’re not saying, but I suspect it’s down to fixing some issues in the Exchange Online transport service to make sure that messages sent from an email alias work properly in every circumstance.

Continual Access Evaluation Enabled for Critical Azure AD Events in Microsoft 365 Tenants

On January 10, Microsoft announced that the base Office 365 workloads support Continuous Access Evaluation (CAE) for critical Azure AD events like password changes or account deletions. Although you can take CAE even further with conditional access policies, giving Exchange Online, SharePoint Online, and Teams the ability to react to critical events in almost real-time is a very big thing indeed.

Microsoft 365 DLP Switches from Envelope to Header for Sender Evaluations

To make Microsoft 365 DLP policies work like Exchange transport-rule based DLP, a January change will switch evaluation of sender conditions away from envelope information to message headers. Although this change might seem to be something beloved of email geeks, it’s actually an important update for organizations who want to move away from ETR-based DLP to Microsoft 365 DLP policies.

Microsoft Upgrades Exchange Online Dynamic Distribution Lists

Microsoft is changing the way the Exchange Online transport service resolves the membership of dynamic distribution groups. Instead of doing this when someone sends a message to a dynamic group, Exchange resolves the membership once daily and whenever the recipient filter changes. It’s a reasonable approach designed to make messages move faster and more reliably, and it’s similar to the way that Azure AD dynamic groups maintain their memberships, so it shouldn’t make much difference.

Some Microsoft 365 Features Highlighted at Fall Ignite 2021 You Can Use Now

To help you recover from the blizzard of Microsoft 365 information released at Fall Ignite 2021, here are some notes about features and functionality you might have missed. Like any list created by a conference (virtual) attendee, it reflects my interests and what I was looking for. Feel free to disagree on the importance of any or all of the topics discussed here… and suggest some of your own in the comments.

Improved DKIM Configuration Page is Prompt to Check Domains

A new Microsoft 365 DKIM management page is a good prompt to check that all domains used to send email in n Office 365 tenant are configured properly for DKIM. The process of enabling DKIM and key rotation is easily done through the GUI or PowerShell once the correct CNAME records are in DNS.

OWA Adds Full Support for Send from Proxy Address (Mailbox Aliases)

A recent update to OWA adds the option to allow users to choose which proxy addresses assigned to a mailbox they would like to send messages from. It’s a small change which completes the client support for the earlier server-side update to allow users to send using mailbox proxies, and it makes using proxy addresses more approachable and useful. OWA also includes a drop-down list in the compose message screen to allow users to select an address to send from, and makes sure that message headers are updated correctly so that messages go back to the right address.

How Exchange Online Uses Archives to Offload Recoverable Items Storage

A change rolling out in mid-October will remove storage pressure on the Recoverable Items structure in Exchange Online mailboxes by offloading some data to archive mailboxes. The idea is a good one because it means that the storage allocated to Recoverable Items won’t fill up and require intervention so often. Users won’t know anything about what’s happening under the covers as it’s all hidden from view.

How to Find Exchange Online Archive Mailboxes Close to the New 1.5 TB Limit

A 1.5 TB limit applies to Exchange Online archive mailboxes from November 1, 2021. In this article, we use PowerShell to report how close expandable archives are to the new limit. In reality, not many archive mailboxes will approach the new limit, but it’s nice to know things like the daily growth rate for an archive and how many days it will take for an archive to reach 1.5 TB. All whimsical stuff calculated with PowerShell!

New Sender-Recipient Limits for Exchange Online Coming in September 2021

Exchange Online already imposes limits on the number of messages a mailbox can receive per hour. New limits will restrict the number of messages individual senders can send to a third of the overall limit. The restriction doesn’t apply to senders with an Exchange Online mailbox in the same tenant. And if a mailbox runs into a limit, it features on the splendidly named Hot Recipients report. What’s not to like about that.

Q&A: How to Send Email Using Proxy Addresses with Exchange Online

Exchange Online supports the ability to send email using any SMTP proxy address assigned to a mailbox. Following the announcement of the feature, users had many questions including what clients can be used. Here are some common questions and answers about the feature, including some PowerShell to report the set of proxy addresses assigned to user mailboxes.

New Invoice Payment Phishing Attack

A new phishing attack is circulating from an Office 365 tenant. The attack attempts to lure recipients into clicking a link to download a document. The phishing email is not quite as crude as other attempts and might lure users into doing the wrong thing, especially as the message is delivered to inboxes.

How to Enable and Use Exchange Online’s External Email Tagging Feature

Exchange Online tenants can activate external email tagging, which causes Outlook clients (not desktop yet) to highlight messages received from external domains. The feature can replace custom implementations to mark external email, usually done with transport rules. It’s easy to implement and control, but the mail tip offering to block an external sender seems a little over the top.

Teams is the Most Difficult Microsoft 365 Application to Backup

Because it sits on top of so many Microsoft 365 components, Teams is easily the hardest Office 365 workload to backup. You can try to backup Teams by copying its compliance records stored in Exchange Online, but that’s only a partial (and bad) solution that utterly fails to take the full spectrum of Teams data into account.

How to Configure OWA, Outlook Mac, and Outlook Mobile to Create Online Meetings by Default

Changes coming in May and June will allow organizations to make online meetings the norm when created by OWA or Outlook mobile clients. You can control the feature at the organization level and allow individual mailboxes to override the organization setting.

Upgrades Available for Exchange and SharePoint PowerShell Modules

Microsoft has published updates for the Exchange Online management and SharePoint Online PowerShell modules. Generally it’s a good idea to install the latest version of PowerShell modules for the different Office 365 products, but beware of some gotchas that await the unwary…

How to Report MailItemsAccessed Audit Events

Microsoft has released information about high-value Office 365 audit events and audit event retention policies. Both are part of a Microsoft 365 Advanced Audit offering. The MailItemsAccessed event is the first high-value audit event (we can expect more) and the retention policies are used to purge unneeded events from the Office 365 audit log.

Why Basic Authentication for Exchange Online is So Bad

Some doubt that Exchange Online will disable basic authentication for five email connection protocols in October 2020. The refrain is that it will be too hard for customers. Well, it might be hard to prepare to eliminate basic authentication, but if you don’t, your Office 365 tenant will be increasingly threatened by attacks that exploit known weaknesses.

Microsoft Retreats From 1TB Limit for Auto-Expanding Archives – For Now

In November, Microsoft set a 1TB limit for Exchange Online auto-expanding archive mailboxes. Now they’ve retreated and the latest service description says nothing about a limit. The two changes in the service featured little or no customer communications and a total lack of any supporting material, like administrative controls to help manage archive mailboxes approaching the limit. While a limit has gone for now, it will be back.

Testing the New Exchange Online REST-based PowerShell Cmdlets

Nine new REST-based PowerShell cmdlets are available for Exchange Online. They offer the prospect of better performance and reliability. Here are the code samples we used to test the new cmdlets for a theater session delivered at the Microsoft Ignite 2019 conference. Anyone wanting to explore the new cmdlets can use these examples to get going.

Microsoft Clamps Down on Auto-Expanding Archive Mailboxes

In a surprise development, Microsoft reversed course for Exchange Online auto-expanding archives and imposed a 1TB limit. The promise of a bottomless archive that continually expanded to cope with user data is removed. Although it’s reasonable for Microsoft to restrict the consumption of resources, suddenly implementing a limit is not, especially when you don’t communicate with customers.

Microsoft Breaks PowerShell Command Logging in Exchange Online Admin Center

The ability to see the PowerShell commands executed by Exchange administrative centers has existed since Exchange 2007. Now something has changed in Exchange Online and the command log is blank. It’s sad because many administrators learned to use PowerShell by examining how Microsoft used it to manage Exchange. Let’s hope that Microsoft fixes this bug soon.

Outlook Increases 500 Shared Folder Limit to 5000

Microsoft has implemented a new synchronization mechanism in Outlook ProPlus to deal more efficiently with shared folders. The new approach increases the limit from 500 to 5,000 folders and is a more elegant and precise solution. Users who manage other peoples’ mailboxes will appreciate the change after they install build 11629.20196 or later.

Add Teams Channel as an Exchange Mail Contact

Teams allows users to send email to channels via special email addresses. Those addresses aren’t very user-friendly, but you can add them as mail contacts so that channel addresses show up in the Exchange GAL. It’s easy to do and makes it much easier for people to email Teams channels. That is, until someone removes the channel email address…

The Side-effects of Using Address Book Policies to Limit Teams Search

You can use Exchange Address Book Policies (ABPs) to limit the ability of Teams users to chat with each other. Everything works as expected until you look for some new teams to join only to find that Teams can’t suggest any teams to you. The problem seems to be with filtering the set of teams returned by the Microsoft Graph to take account of the scope applied to the user. At least, that’s what I think is going on.

Outlook’s Option to End Appointments and Meetings Early

Outlook for Windows (ProPlus or click to run) now boasts settings to allow users to schedule meetings and appointments to end some minutes earlier than expected. Brian Reid is very excited by the prospect, but we’re not sure if this qualifies as one of StĂĄle Hansen’s famous lifehacks. In any case, ending meetings early won’t solve the problem of badly-organized or managed meetings or how people behave during meetings, but it might give you a quiet feeling of satisfaction to have a neater calendar.

Microsoft’s “New Migration Experience” from G Suite to Exchange Online

Microsoft announced a new migration experience from Google G Suite yesterday, which is nice. Under the covers, the venerable Mailbox Migration Service (MRS) does the work to extract mailbox data from Gmail using IMAP4 and moves it to Exchange Online. But after the move is done, there’s still lots of work to do to help users make the cultural change to their new mailbox in the cloud.

Outlook’s Background Moves

Outlook logo

It’s hard for a program that’s been around for 22 years to surprise, but Outlook has done it by introducing background moves. The implementation is good and it closes a gap that’s existed in Outlook for a very long time. So long that most Outlook users probably assumed that the program would never mend its ways. But then again, because people don’t move items between folders like they used to, perhaps no one cared.

Microsoft Halts Deployment of MailItemsAccessed Audit Records

Announced in January, paused in March – that’s the fate of the MailItemsAccessed audit record generated by Exchange Online for the Office 365 audit log. Microsoft found some problems that they are fixing, which is good (because you want audit data to be reliable). And when the fixes are available, the deployment of the new audit record will restart.

The Irritation of Exchange Online’s Inconsistent Mail Tips

MailTips are a pretty useful way of drawing the attention of users to potential issues with email. Exchange Online supports several MailTips, but Outlook clients insist on supporting MailTips in different ways. It’s a small but irritating part of Exchange Online that could be done better.

Office 365 Exposed Episode 14 Now Available

Last week, we taped episode 14 of the Office 365 Exposed podcast in Building 27 of Microsoft’s HQ in Redmond. Topics covered include battling attacks on Exchange, the need to upgrade old Exchange versions, Teams announcements at Enterprise Connect, and how the base Office 365 workloads handle retention storage. We think it’s an interesting episode. Get it from iTunes now!

Phishing: Your Document Has Been Completed

Phishing attacks through email happen all the time. A new relatively crude one arrived today. It’s easy for the trained eye to detect phishing, but do your Office 365 admins know how to use the tools available in Exchange Online Protection to suppress malware, and do your users know the signs of bad email? In this case, it’s an invitation to click to get to a PDF document to bring you to digitaloceanspaces.com. Some interesting things might happen afterwards, but I really don’t want to find out what occurs when I click the link.

Microsoft 365 Licensing, Yammer and Teams, Office DPIA, and Exchange

Office 365 changes all the time, which is good because it keeps the Office 365 for IT Pros writing team busy and happy. Discussions this week included Microsoft’s response to a Dutch DPIA, the effect large Teams have on Yammer, how Exchange Online validated a fix to a security problem, and graphics to help understand the components of the Microsoft 365 E3 and E5 plans.