Managing Dynamics 365 Business Central takes more than daily effort. It demands the right setup from day one. Miss a notification. Mishandle an update window. Overlook a guest user email failure. Any of these mistakes can turn a routine upgrade into a full support crisis.

At Vaden Consultancy, we work with businesses on these exact problems every day. Over the years, two issues keep coming up. First, admins do not receive update notifications on time. Second, guest users cannot send emails from Business Central. Both problems are fixable. This blog shows you how.

Part 1: Managing Business Central Update Notifications the Right Way

Why Update Notifications Matter

Microsoft releases two major updates for Business Central each year. Open the Business Central Admin Center Notifications Guide to get started. Microsoft also pushes monthly minor updates in between.

As an internal admin or partner, you control when these updates run. You use the Business Central admin center to set the timing for each environment. You also choose who gets notified when an update is ready.

That second part is where most teams make mistakes. We have walked into client environments where the only notification recipient was a former employee. No one had checked that inbox in months.

What Happens When You Miss a Notification

Before every major update, Microsoft checks your per-tenant extensions for compatibility issues. When Microsoft finds a problem, it sends an email to your notification recipients. If that email lands in a dead inbox or a spam folder, your team learns nothing. You get no time to fix the conflict before the update goes live. That is how production environments break on Monday mornings.

How to Protect Against Missed Alerts

Take two steps right now.

First, whitelist the sender address no-reply-dynamics365@microsoft.com in your spam filters. Microsoft sends all update alerts from this address. Make sure it reaches your inbox every time.

Second, add at least one active admin email address to your notification recipient list. Do not leave this to chance.

How to Set Up Notification Recipients

Who Can Access the Settings

You need either a Global Administrator role or a Dynamics Administrator role to manage notification recipients. Without one of these roles, the settings are not visible to you.

Steps to Add Recipients

Open the Business Central Admin Center Notifications Guide to get started. You will see a list of your BC environments. Select Notification Recipients from the left-hand menu. Add or remove email addresses as your team changes.

Do not assume this list updates itself. It does not. Review it every time someone joins or leaves the admin team.

Use a Shared Inbox

We always recommend setting up a shared mailbox or distribution group as one of your recipients. This way, no single person’s departure leaves your team blind. Everyone stays informed, and the list never goes stale.

Part 2: Setting the Right Update Window

What the Update Window Does

The update window tells Business Central when it can run updates. You set a start time and an end time for each environment. You also choose the time zone.

Every environment has a default window: 8:00 PM to 6:00 AM local time. This default works well for most businesses. But it is worth reviewing.

When to Change the Default Window

Some businesses run batch jobs late at night. Others operate across multiple time zones. In both cases, the default window may conflict with active usage. Check each environment and adjust the window to match real business hours.

What Happens If an Update Does Not Finish in Time

If an update does not complete before the window closes, Business Central cancels it. Microsoft then reschedules it seven days later. Your notification recipients get an email about the delay.

This safety net is helpful. But if your window is too short, updates will keep getting pushed back. Make the window wide enough for updates to finish in one run.

How to Schedule Updates on Your Own Terms

You do not have to wait for Microsoft to push updates automatically. When a new version becomes available, all notification recipients get an email. You also see a notice inside the Business Central admin center.

Use this time wisely. Follow these steps every time:

1. Schedule the update on your sandbox environment first
2. Test your extensions and customizations
3. Confirm everything works as expected
4. Then schedule the update for your production environment

This approach is standard practice in any well-run Dynamics 365 Business Central implementation. Build it into your change management process from the start.

Part 3: Moving Notifications to Microsoft 365 Message Center

Why This Change Matters

The Business Central admin center notification list is not the only place to track updates. Microsoft also posts environment lifecycle events to the Microsoft 365 Message Center.

Over time, the emails sent to your recipient list will cover fewer events. More alerts will appear only in Message Center. Microsoft recommends that all relevant people sign up for Message Center emails now, before the full transition happens.

How to Sign Up

Go to the Microsoft 365 admin center. Select Health, then Message Center. Open Preferences and turn on email notifications. Add your email address and up to two others.

A Note for Delegated Admins

If you manage a client’s tenant as a delegated admin, you may not be able to sign up yourself. In that case, ask the internal admin to add your email or a group address as a recipient. This quick fix prevents a lot of missed alerts down the road.

Part 4: Fixing Email Connector Issues for Entra B2B Guest Users

The Problem Most Admins Do Not Expect

Many Business Central environments include Entra B2B guest accounts. These are external users accountants, cross-company staff, or partner contacts. If you manage these users, you have probably seen this issue: the built-in email connectors do not work for them.

This is not a bug. It is a known limitation based on Exchange Online licensing rules.

Why Guest Users Cannot Send Email

Every user who sends email from Business Central needs a valid Exchange Online license. Guest users do not have one in your tenant. Their mailbox lives in their home organization. Your Business Central environment cannot send email on their behalf through your Exchange setup.

Microsoft states this clearly: external users such as delegated admins and external accountants cannot use the Microsoft 365 or Current User email connectors to send messages from Business Central.

How Guest Authentication Works

When a B2B guest signs into your Business Central, they authenticate against their own organization, not yours. In July 2025, Microsoft updated this sign-in flow. Guest users now see their home organization’s login page first. After they log in, they return to your environment. This update made sign-in clearer. But it did not fix the email connector problem.

Part 5: Workarounds That Actually Work

Option 1: Use a Shared SMTP Mailbox

Set up an SMTP connector using a shared mailbox that belongs to your tenant. This mailbox sends email on behalf of guest users. The downside is that all outbound email from guest users comes from this shared address. Some businesses find this acceptable. Others need email to show the guest’s own name and address.

Option 2: OAuth 2.0 SMTP with Cross-Tenant Setup

This option became available in 2025 release wave 2 (version 27.2 and later). It lets Business Central send emails through the SMTP connector using OAuth 2.0 client credentials. It also supports cross-tenant scenarios. This means your app registration can live in one Microsoft Entra tenant and still send email from another.

To set this up, you need to:

• Create an app registration in Azure portal
• Grant the SMTP.SendAsApp permission in Exchange Online
• Configure the credentials inside Business Central

This setup takes careful planning. But it produces a secure and scalable result. It works especially well for managed service providers who handle Business Central for multiple clients in separate tenants.

Option 3: Power Automate as an Email Bridge

Use a Power Automate flow to handle outbound email for guest users. The flow runs under a licensed member account. Business Central triggers the flow, and the flow sends the email. This adds some complexity. But it completely avoids the connector limitation.

Part 6: Getting Licensing Right for Guest Users

The Cleanest Long-Term Fix

If a guest user sends email from Business Central every day, a guest account may not be the right fit. Consider giving that user a member account in your tenant instead. Or assign them an Exchange Online license that covers their needs.

Guest users carry real limitations. The license they hold in their home tenant does not transfer to your tenant. You must assign them a valid Dynamics 365 license in your environment to give them full access.

Talk About Licensing Early

Raise the licensing question at the start of every Dynamics 365 Business Central implementation that involves guest users. Fixing licensing decisions after go-live costs time and money. Getting it right upfront is always faster and cheaper.

Part 7: When Custom Development Is the Answer

Some businesses need guest users to trigger email workflows directly inside Business Central. Standard workarounds may not be enough for these cases. This is where Dynamics 365 Business Central development can help.

What Custom Extensions Can Do

Custom extensions can route email through a service account. They can connect to a third-party SMTP provider. They can also log email requests to a queue and process them using a licensed account in the background.

Work with an Expert First

None of these solutions are simple to build. But they solve problems that out-of-the-box options cannot. If you go this route, involve an experienced Dynamics 365 Business Central consultant early. Poor architecture here creates security gaps and compliance risks that are hard to fix later.

Summary: Your Admin Checklist

Use this checklist to get your setup in order today.

For Update Management:

• Review your notification recipient list across all environments
• Remove old email addresses and add current team members
• Add a shared inbox or distribution group as a recipient
• Whitelist no-reply-dynamics365@microsoft.com in your spam filters
• Review and adjust update windows for each environment
• Always test major updates on sandbox before pushing to production

For Guest User Email:

• Find out which users are B2B guest accounts before they report problems
• Decide on an email workaround during the implementation phase, not after go-live
• Check whether heavy email users need a member account and proper licensing instead
• Switch to OAuth 2.0 for SMTP if you have not done so yet

Final Thoughts

Managing Business Central well means more than keeping systems running. It means sending the right notifications to the right people. It means building the right architecture before small gaps turn into big incidents.

Guest user email is one area where poor planning shows up fast. Users cannot send emails. Tickets pile up. Workarounds get built under pressure. None of that has to happen.

At Vaden Consultancy, this is the work our team does every day. We guide businesses through Dynamics 365 Business Central implementation. Every engagement starts with getting the fundamentals right.

If any of this sounds familiar, reach out. We are happy to review your current setup and show you what a better configuration looks like.