Exchange 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!Could any one explain Exchange Server SE Licensing Model?
I have the following M365 licenses in my education tenant: Microsoft 365 A5 without Audio Conferencing (Student Use Benefit) As per my understanding, each user requires an A3/A5 license to access their mailbox on an Exchange Server (Exchange SE). Since A3/A5 licenses already include Exchange Online, do we still need to assign these licenses to each on-premises user, or is this only for compliance purposes? For example, if we have 100 on-premises users, must all 100 users be assigned A3/A5 licenses in Microsoft 365? Reference articles are below. Microsoft Product Terms Please correct me if I am wrong.
Update Dynamic Distribution List
we are a hybrid environment, running exchange 2019 and have a few DDLs which have been around from previous exchange versions. One of the DDLs i need to modify is the below. Its hard to read and i am trying to work out where i add the extra fields i want to include. I am looking to add another custom attribute and possibly include members of a security group. Is there anyway to make this easier to read so i know where to add things? Any other tips? ((((((((((((((((((((((((((Company -eq 'Contoso') -and (CustomAttribute4 -eq 'City'))) -and (((((CustomAttribute7 -eq 'Group') -or (CustomAttribute7 -eq 'Contractor'))) -or (CustomAttribute7 -eq 'Permanent'))))) -and (((RecipientType -eq 'UserMailbox') -or (((RecipientType -eq 'MailUser') -and (CustomAttribute12 -ne 'Excluded'))))))) -and (-not(Name -like 'SystemMailbox{*')))) -and (-not(Name -like 'CAS_{*')))) -and (-not(RecipientTypeDetailsValue -eq 'MailboxPlan')))) -and (-not(RecipientTypeDetailsValue -eq 'DiscoveryMailbox')))) -and (-not(RecipientTypeDetailsValue -eq 'PublicFolderMailbox')))) -and (-not(RecipientTypeDetailsValue -eq 'ArbitrationMailbox')))) -and (-not(RecipientTypeDetailsValue -eq 'AuditLogMailbox')))) -and (-not(RecipientTypeDetailsValue -eq 'AuxAuditLogMailbox')))) -and (-not(RecipientTypeDetailsValue -eq 'SupervisoryReviewPolicyMailbox')))) -and (-not(Name -like 'SystemMailbox{*')) -and (-not(Name -like 'CAS_{*')) -and (-not(RecipientTypeDetailsValue -eq 'MailboxPlan')) -and (-not(RecipientTypeDetailsValue -eq 'DiscoveryMailbox')) -and (-not(RecipientTypeDetailsValue -eq 'PublicFolderMailbox')) -and (-not(RecipientTypeDetailsValue -eq 'ArbitrationMailbox')) -and (-not(RecipientTypeDetailsValue -eq 'AuditLogMailbox')) -and (-not(RecipientTypeDetailsValue -eq 'AuxAuditLogMailbox')) -and (-not(RecipientTypeDetailsValue -eq 'SupervisoryReviewPolicyMailbox')))
Exchange SE product key Clarity
Hi All, After installing the Exchange SE server, the following parameters appeared when I ran the command. Can we leave these statuses as they are until Microsoft provides the new CU and product key ? Please confirm Get-ExchangeServer -Identity newse | fl fqdn,product*,*edition* Fqdn : NewSE.test.local ProductID : Edition : StandardEvaluation IsExchangeTrialEdition : True IsExpiredExchangeTrialEdition : False
Outlook Client unable to search on Server. 'Server unavailable. 12 months of results shown.'
I am getting this error with a client on a main workstation, but another workstation searches via Outlook works OK One workstation is running Office 365 Pro Plus 1902 - not working Another Laptop runs Office 2016 and works My process to migrate from 2013 to 2019 included - making MAPI enabled. I added 3 servers that I will DAG, asnd eventually take down the 3 2013 servers (but they are still up and running). I ran the following (with my server names) on my 3 new servers 1 Get-OutlookAnywhere -Server srvexc2019 | Set-OutlookAnywhere -InternalHostname ex02.mydomain.com -InternalClientAuthenticationMethod Ntlm -InternalClientsRequireSsl $true -ExternalHostname ex02.mydomain.com -ExternalClientAuthenticationMethod Basic -ExternalClientsRequireSsl $true -IISAuthenticationMethods Negotiate,NTLM,Basic 1 Get-EcpVirtualDirectory -Server srvexc2019 | Set-EcpVirtualDirectory -InternalUrl https://ex02/mydomain.com/ecp -ExternalUrl https://ex02.mydomain.com/ecp 1 Get-OwaVirtualDirectory -Server srvexc2019 | Set-OwaVirtualDirectory -InternalUrl https://ex01.mydomain.com/owa -ExternalUrl https://ex02.mydomain.com/owa 1 Get-WebServicesVirtualDirectory -Server srvexc2019 | Set-WebServicesVirtualDirectory -InternalUrl https://ex02.mydomain.com/EWS/Exchange.asmx -ExternalUrl https://ex02.mydomain.com/EWS/Exchange.asmx 1 Get-ActiveSyncVirtualDirectory -Server srvexc2019 | Set-ActiveSyncVirtualDirectory -InternalUrl https://ex02.mydomain.com/Microsoft-Server-ActiveSync -ExternalUrl https://ex02.mydomain.com/Microsoft-Server-ActiveSync 1 Get-OabVirtualDirectory -Server srvexc2019 | Set-OabVirtualDirectory -InternalUrl https://ex01.mydomain.com/OAB -ExternalUrl https://ex02.mydomain.com/OAB 1 Get-MapiVirtualDirectory -Server srvexc2019 | Set-MapiVirtualDirectory -InternalUrl https://ex02.mydomain.com/mapi -ExternalUrl https://ex02.mydomain.com/mapi I can search OK from online owa Any Idea how to fix the search on Outlook clientFederation Trust Gateway broken - OrgCertificate cannot be uploaded
Hey guys, last week we have done Windows Server updates and this broke some stuff. Some certificates have been unbound and so on. Until then the full classic hybrid worked quite good in our Exchange Server 2016 CU23 environment. We are just in the process of upgrading/migrating. But after this point of time the On-Premises users stopped being able to see the calendars of the cloud users, other way around still worked. So we started trying to fix the hybrid deployment with several runs of the HCW (which is always fine) and rebuilding the organizational relationship and the trust federation gateway. This was quite exhausting, as we updated a bunch of domains in global DNS several times. Currently, neither direction is functioning. Now it looks like the Federation Trust Gateway is in an inconsistent state. When I try... Set-FederationTrust -Identity "Microsoft Federation Gateway" -PublishFederationCertificate then I get the message, that the rollover certificate (OrgNextPrivCertificate) is not set and that I only can publish, when this is done. When I try to define a rollover certificate, then I get the message, that the rollover certificate cannot be set until the OrgCertificate has been published. So, we have a chicken-and-egg situation here. Thanks for any help.How to Find Active EWS-Based Apps in a Microsoft 365 Tenant
Microsoft will retire Exchange Web Services (EWS) from Exchange Online on October 1, 2026. A new usage report helps tenants understand what apps use EWS. Many of the apps are likely to be first-party (Microsoft) apps, but some might be third-party apps developed externally or internally. Those apps need to be retired or upgraded to use Graph APIs. Time is slipping away to do the work. https://office365itpros.com/2025/04/29/exchange-web-services-apps/
Exchange 2019 AvailableNewMailboxSpace
Hello! Colleagues, have you encountered a situation where Exchange 2019 does not provide accurate information about the amount of free space in databases (AvailableNewMailboxSpace) via EMS? Using this command: Get-MailboxDatabase -Status | Sort-Object Name | Select-Object Name,@{Name=‘DB Size (GB)’; Expression={[math]::Round($_.DatabaseSize.ToGb(),2)}},@{Name=‘Free Space (GB)’;Expression={[math]::Round($_.AvailableNewMailboxSpace.ToGb(),2)}} | Format-Table -AutoSize Exchange 2016 displays the information correctly, but 2019 does not display it correctly in gigabytes or the numbers are unclear. Do you know of another way? Thank you!
