Recent Discussions
Issue with certificate renewal for exchange Edge Transport Server
Hello team, I have come across a very particular problem I deployed 2 exchange server 2019 with one edge transport server When we are renewing the Certificates with wildcard certificate on both mailbox server ,and on edge transport server ,it is impossible for me to renew the edge subscription It says the cerificate is in "doublon" (repetitive) on one of the Exchange servers.I have always been using same certificate on exchange server be it edge or mailbox I tested a bogus different certificate on mailbox and on edge,only then th e edge sync works Did anybody come across this issue. ThanksOAB download fails after hybrid mailbox move.
Hi folks, I'm posting this query here as I doubt anyone in the Outlook forums would have the necessary Exchange hybrid knowledge. I run a classic hybrid Exchange environment where Exchange Server 2019 CU15 is the on-premise platform. Authentication is provided by on-premise AD FS, with the accounts being synchronised from on-premise via AAD Connect. I've just moved my on-premise mailbox to Exchange Online via New-MoveRequest and for the most part, everything is fine. One thing that possibly isn't fine - going off the Bits-Client event log is the regular offline address book downloads, where I'm seeing regular failures in the event log and through double-checking with bitsadmin.exe. The initial address book synchronisation worked as the view in Outlook is fully populated, however, I expect that future changes likely won't come through. bitsadmin output Event log output (There's numerous events to choose from - this is the one I'm most curious about.) The BITS service provided job credentials in response to the UNIDENTIFIED authentication challenge from the outlook.office365.com server for the Microsoft Outlook Offline Address Book <guid> transfer job that is associated with the following URL: /OAB/<guid>/oab.xml. The credentials for the <sid> user were rejected. When the mailbox was on-premise, the OAB came from the Exchange Server - no surprise there, where post migration it can be seen from the bitsadmin output it now comes from outlook.office365.com. Perhaps that's also to be expected - I don't know, but it makes sense given the move. What alerted me to there potentially being an issue is the systray icon frequently gets stuck on the "synchronising" icon, and running a manual full OAB sync from within Outlook fails to complete. After an extended "hang" period, the sync window eventually times out with the error shown above (the protracted UI behaviour would appear to be due to the large number of retries). Dropping the BITS job URL into Edge simply returns a HTTP 503, which doesn't necessarily strike me as a problem. After all, I'm unable to provide a BEARER token using this method. I haven't yet tried via PowerShell as it only occurred to me now but perhaps I'll do so after posting this. Searching on this error and scenario has turned up nothing useful. I have also checked and compared event log entries from an Azure AD-native account, where it's a mixed bag of successful OAB BITS downloads and unsuccessful ones that feature the same symptoms as above, which offers up the possibility this might be a transient service-side error (though I'm not leaning heavily towards this). Has anyone else encountered this issue and resolved it? Is it even an issue to begin with, or is this expected behaviour? I'm unsure what to make of the symptoms. Cheers, Lain
Add-PublicFolderClientPermission: Object reference not set to an instance of an object.
Running into an issue with adding public folder permissions in Exchange Online. I've used this PowerShell script for a few years without any issues, but suddenly getting this error no matter what I try. I do have Owner permissions and there are Default and Anonymous permissions on the public folder, tried completely removing and reinstalling the ExchangeOnlineManagement module as well. Anyone else having this problem? $PF = Get-MailPublicFolder -Identity "\pf1" $User = Get-User -Anr "User1" $AccessRights = @( "ReadItems", "CreateItems", "EditOwnedItems", "EditAllItems", "FolderVisible" ) Add-PublicFolderClientPermission -Identity "\$($PF.Id)" -User $User.UserPrincipalName -AccessRights $AccessRights -Verbose VERBOSE: Returning precomputed version info: 3.9.2 VERBOSE: Requested HTTP/1.1 POST with 227-byte payload VERBOSE: Received HTTP/1.1 response of content type application/json of unknown size VERBOSE: Query 1 failed. Add-PublicFolderClientPermission: Object reference not set to an instance of an object. Thank you
Emails from Azure Communication Services (ACS) are treated as external emails
When using Azure Communication Services (ACS) Email, messages are delivered to Microsoft 365 as external mail, even if the system sending them belongs to my own organization. This behavior can be expected because ACS sends emails from Microsoft’s cloud infrastructure rather than directly from my tenant. As a result, Distribution Groups (DG), Dynamic Distribution Groups (DDG), or Mail-enabled Security Groups (SG) that are configured to accept messages only from internal senders will reject these emails. The common workaround is to enable “Allow external senders” on the group. However, we don't want to open the group to the entire internet. Does anyone else have the same experience? What is the best solution, exchange transport rules? Thanks!TEST-OAuthConnectivity | The remote server returned an error: (403) Forbidden
Hello Exchange Tech Community, I have setup a lab environment of Exchange Server 2016 in Hybrid Configuration. I can successfully onboard and offboard mailboxes. OnPrem Exchange Server is I have a Microsoft 365 Business Basic subscription for Exchange Online. Entra ID Sync is working seamlessly. Email flow between OnPrem and EXO and vice versa work perfectly. When I am testing OAuth functionality from OnPrem to EXO, I am getting this error highlighted in yellow Do I need assign any role to synchronized user in Entra ID ? Currently, they are just MEU in EXO. When OAuth is test from EXO to OnPrem, I am getting this error Please advise.Microsoft Rushes High-Volume Email to General Availability
Almost two years after it first previewed, Microsoft is making the High-Volume Email (HVE) solution generally available in March 2026. HVE runs on a pay-as-you-go basis, but Microsoft won’t start charging tenants for sending email until May 2026. Two months should be enough for people to decide if they want to use HVE for internal communications as it has no ability to send external email. https://office365itpros.com/2026/03/09/hve-ga/Measuring KPIs like Response Times for Shared Mailboxes
Shared mailboxes are not CRM systems. However, many Microsoft 365 tenants use shared mailboxes to handle customer queries and then want to measure KPIs such as agent responsiveness to customer queries or the number of queries handled per agent in a month. As explored in this article, it’s possible to use the Microsoft Graph and PowerShell to extract some KPI-like data from shared mailboxes. https://office365itpros.com/2026/03/05/shared-mailbox-kpi/
Proper whitelisting of microsoft.com on dnswl.org
I keep having the issue that system-generated e-mails, e.g. on Trace Reports get classified as spam by the receiving e-mail provider. The sender address is email address removed for privacy reasons and the e-mails go to my M365 mailbox and are redirected to my external monitoring mailbox with that e-mail provider. The e-mail provider calculates a score that includes checking the sender's IP address 52.101.69.91 with dnswl.org . Unfortunately, that address is only whitelisted for outlook.com and some secondary domains, but not for microsoft.com. Of course, the issue also occurs with mailto:email address removed for privacy reasons and other IP addresses, so this is an example. It started to occur around two weeks ago, not sure if the provider changed policies or Microsoft changed the whitelisting; of course the provider refuses to overrun dnswl.org it, e.g. by own whitelisting. Who at Microsoft could I ask to fix that kind of issues? I don't find any appropriate category in their support menues, M365 support says the cannot help (TrackingID#2603031420001611). Thanks in advance for any hints, this is my first posting here, so please forgive me, if this is a dumb question.
Report for email reply time for shared mailbox
Hi All, i am looking to crate report for management for our KPI. Management want to to know how quick teams are replying to email once it's landed to mailbox. Also, average reply time for the particular mailbox for a day or week or month. if nay one know how to achieve this please let me know it will be grate help. Thanks, PreyashExchange online - track deleted mail
I am 365 admin and see quite often people rapport "all my mails are in deleted post - and I have done nothing" or similar What is the best practice to investigate that. I know in powershell I have made some auditsearches, where it rapports like softdelete, hardelete etc - but is there any more specific way proving that the user actually did in on his own ? - I know with retention policies it is hard delete - but just wondering what the best practice is like to prove to the user that this is the user. Just write that it is soft deleted and means user have done it, often the user think is not understandableExchange database dismounted due to NTFS file extent limit reached – unexpected outage
Hi everyone, We experienced a serious outage on our Exchange 2016 server recently, and I wanted to share what we found during the root cause analysis – in case it helps someone else avoid the same scenario. Summary: After digging deep, we discovered that the issue was caused by the NTFS file system hitting its internal file extent limit on the .edb file. Once this threshold was reached, the database could no longer grow, and the system dismounted the database unexpectedly. No prior warning, just service interruption. Details: The .edb was around 1.2 TB in size. This isn’t a limit on database size itself — it’s about how fragmented the file is on disk. Once NTFS couldn’t track any more extents, the database stopped working. Microsoft doesn’t publish a clear fix for this; only scattered references to similar behavior in past cases. What we did: Created a fresh, clean database. Manually moved user mailboxes into the new DB. The old database couldn't be mounted anymore, so we brought the system live without historical mail – just to maintain continuity. We're now working on extracting data from the unmounted .edb using third-party tools. Looking for thoughts: Has anyone else hit the NTFS extent wall with Exchange? How do you monitor extent growth proactively? Did switching to ReFS solve this for you long-term? Open to any input or similar experiences – appreciate it in advance. Thanks!Retire last Exchange Server but keep directory sync
Hello all -- I'm looking for guidance on the recommended way to retire our last Exchange 2019 server while maintaining directory synchronization in our environment. We do not have any mail flowing through our exchange server, never have. It was only installed 10 years ago for a hybrid deployment. I believe one supported path is to stand up a member server and install the Exchange Management Tools on it. Given that Exchange 2019 is already out of support, is the the long term path moving forward? I've also read about an attribute "IsExchangeCloudManaged". In this scenario, I can set this on a per-mailbox basis and manage attributes such as proxyaddresses, extension attributes, and other non-AD-managed attributes. Is this the more forward path to take? Thinking about our user provisioning process now, we have a PowerShell script that creates the user in AD and connects to our hybrid Exchange server to Enable-RemoteMailbox. In this scenario, we would still create the user in AD, wait for the sync to happen, then enable the IsExchangeCloudManaged. Would this now provide the ability to manage additional addresses, or even, shared mailboxes without having to migrate from AD --> EXO - all while keeping AD in sync with cloud mailboxes? Am I thinking about this correctly? Thanks for any insight sb
Dynamic Distribution Group with no Disabled Accounts
Hi I'm trying to build a few Dynamic Distribution Lists in Exchange Online and want to only include Active Users (i.e., users that are marked "Active" in Azure AD). I've tried using the UserAccountControl attribute (-eq 514 or -ne 514 - both are returning the same results, which is strange), but it still includes user accounts that are disabled. This is how my recipient filter looks like: RecipientType -eq 'UserMailbox' -and UserAccountControl -ne 514 What's the best way to achieve this in Exchange Online? Thanks Taranjeet Singh
Exchange 2010 to Microsoft 365 Migration – Recommended Approach and Tools
I’m looking for guidance on migrating Exchange 2010 (on-premises) to Microsoft 365 / Office 365. Is a direct migration from Exchange 2010 supported, or is an intermediate hop (such as upgrading Exchange or setting up a hybrid configuration) required? Additionally, could you please recommend any reliable tools that can help with this migration? I also have a few PST files that need to be migrated as part of the process. I’d appreciate insights on best practices, common challenges, and lessons learned from real-world migrations. Thanks in advance for your help.Teams delegation permission issue with Onpremise Exchange Server
we have migrated the exchange server from 2019 to SE Environment and configure the OAuth 2.0 which is working perfectly but there is one issue that one of the user is using Shared calendar but while he create the meeting invite along with Teams meeting option then everytime it shows an error "please login into the meeting" If anyone works on this case please guide or help us. ThanksExchange Online PowerShell Dumps the Credential Parameter
On February 12, Microsoft announced the deprecation of the Credential parameter for the Connect-ExchangeOnline cmdlet in the Exchange Online PowerShell module. The deprecation won’t affect interactive sessions (which should all be protected by MFA), but it might stop some background jobs running when Microsoft retires the server components that currently support the ROPC authentication flow. Time to check scripts! https://office365itpros.com/2026/02/16/exchange-online-powershell-ropc/DMARC rejection after Exchange upgrade
I'm having problems with inbound emails getting bounced as Undeliverable due to DMARC rejection. For many years I've had my email come through Fasthosts / Livemail to my own domain (qts.org.uk) with catch-all forwarding set to forward everything to my GMail account. Just recently Fasthosts have upgraded their servers to Exchange and I've started getting DMARC rejections from GMail which start Diagnostic information for administrators: Generating server: exchange2019.livemail.co.uk Total retry attempts: 1 (my gmail email address) t1-hex-xprelay.gem.livemail.co.uk Remote Server returned '550 5.7.26 Message rejected by DMARC policy by gmail.com. Please use your own email address as the sender, instead of (sender's email address). [MSG0009]' Which bounce from Fasthosts / Livemail back to my GMail address. My own domain has SPF, DMARC, and DKIM configured I've done a little digging and it appears to only affect senders from originating domains with DMARC set to reject. So either GMail has coincidentally become much more strict (possible) or Fasthosts are somehow failing to forward emails fully transparently. I have spoken to Fasthosts and logged the issue with them and was not impressed so I hope the experts here can offer a solution I can forward to them.
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