2,245 questions with Microsoft Exchange Hybrid Management tags
HCW8001 Error: Unable to Determine the Tenant Routing Domain
Encountering the error HCW8001 Unable to determine the Tenant Routing Domain while running the Hybrid Configuration Wizard (HCW). Below are the relevant log entries observed during the process: 2025.03.05 15:09:31.633 10271 [Client=UX,…
HCW Error - Register Agent
Hybrid Configuration Wizard always stops with error at "Register Agent". Following lines are found in the Log-File: 2025.01.08 16:07:30.742 10333 [Client=UX, fn=SendAsync, Thread=14] FINISH Time=290,0ms Results=NotFound…
How to fix Office 365 Hybrid Configration Wizard cannot sign into M365 ?
We are running Exchange 2016 on server 2016 and have al current patches installed. When trying to run the Office 365 Hybrid Configration Wizard, it fails to sign into M365. The log files gives the following details: 025.02.03 16:06:56.311 ERROR 10251…
O365 Sync Issues After On-Premises Exchange Decommissioning
In a transition from a Hybrid environment to nearly full cloud usage, the on-premises Exchange was shut down due to security concerns, following documentation and recommendations while leaving the schema intact. Currently facing issues managing user…
Exchange server 2013 and Microsoft 365-Hybrid mode
Hi Everyone, We intend to migrate from on-premises Exchange 2013 to Microsoft 365. Can we maintain a hybrid mode with an Exchange server 2013 and move 40-50 mailboxes to O365 for testing for up to a year? (The ultimate goal is to migrate all mailboxes to…
HSTS missing
Hi all, I have an Exchange 2016 hybrid environment and have identified the following vulnerability. Please suggest how to fix it.
SPF and DKIM is faling as emails are getting forwarded to one Cloud Anti-Phisihing Solution
Hello, We are using EOP as our email Gateway and once internet email reaches to EOP we are forwarding that internet email to one Cloud Anti-Phisihing Solution platform and then again email comes back to EOP but due to this routing when EOP check the SPF…
Re-install Exchange 2016 after system corruption
Hi All, Before we open a pay-per-incident(s) MS ticket, I thought I'd lob this scenario out to the community. Our sister organization has a lot of technical debt, both hardware and & software. We needed to get them on Exchange Online, and to do…
unable to add additional email address
Hi All, I am using an Exchange 2016 hybrid environment. We create users on-prem and then migrate them to Exchange Online. I have a user, user1@contoso.com, and I want to add an additional email address, user1-temp@contoso.com, to this user. When I…
unable to delete a DL.
Hi All I have a distribution list (DL) in Exchange Online. However, when I search for it in the Exchange Admin Center or Microsoft 365 Admin Center, I cannot find it. I can see the DL in PowerShell, but not in the GUI. Get-EXORecipient -ResultSize…
Security update for Exchange
Hi All, I am using an Exchange 2016 hybrid environment. My Exchange servers are running on Exchange Server 2016 CU23 Nov24SUv2. We have a third-party vulnerability scanning tool, and it has detected the following vulnerability on my Exchange…
unable to install CU
Hi All, I am trying to upgrade Exchange Server 2016 to the latest CU. I am currently on Exchange Server 2016 CU23 Nov23SU and attempting to upgrade to Exchange Server 2016 CU23 Nov24SUv2. However, I am encountering the following error. Please guide me.
issue of hiding a user from global address list
I have a hybrid Exchange environment with single Exchange 2013 and all mailboxes in M365. I simply liked to use Exchange PowerShell to hide a user from the global address book but received the error. Please advise. Tried: Set-Mailbox -Identity…

"Is a hybrid cloud approach (keeping PHI on-prem while using Microsoft 365 for apps) a recommended and HIPAA-compliant strategy for hospitals moving toward EMRs?"
We are a hospital and school organization that currently operates an on-premises infrastructure, including Exchange servers and all internal applications. Our CEO is interested in moving to the cloud, particularly Microsoft 365 for apps, and potentially…
Exchange Hybrid Migration | When to apply license
Hi all, I had two questions? Is it safe to apply a license when a mailbox has been synced and is suspended waiting for the final cutover? For example the mailbox is being migrated, its now fully synced and suspended, can i apply the license at that point…
Connect-ExchangeOnline: Write-ErrorMessage : Expired or Invalid pagination request. Default Expiry time is 00:30:00
I wrote a script a while back that gets the the UserPrincipalName, DisplayName, LastLogonTime, CreationTime, Inactive Days, MailboxType, AssignedLicenses, ItemCount, MB Size, and Roles from MSOnline and Exchange Online. It works fine on one server and my…
How to fix error Error: CommunicationErrorTransientException:Could not establish trust relationship for the SSL/TLS secure channel with authority
we are running a ybrid environment , we create user mailboxes on our on prem exchange and than migrate the mailbox to exchange online , we have been doing that succesfully up until last week , when it started fsiling for all mailboxes , it stay for the…
Problème connexion compte O365 Outlook
Bonjour, J'ai un problème chez un client où nous avons fait une migration Exchange Server 2010 vers Office 365 dernièrement et il s'avère que depuis quelques jours j'ai 3-4 personnes qui peuvent plus ouvrir leur Outlook avec l'erreur suivante : J'ai…
On premise 2016 to exchange online
Hi all, i have a hosted exchange 2016 with 22 tenanats that I need to migrate. I don't want to install AAD connect or hybrid. Is there a way to do it manually by importing a CSV file? Or do a cutover with selective mailboxes?
Delivery has failed to these recipients or groups
Your message couldn't be delivered. The Domain Name System (DNS) reported that the recipient's domain does not exist. Contact the recipient by some other means (by phone, for example) and ask them to tell their email admin that it appears that their…