Recent Discussions
How do you make a Shared Mailbox the default Send From account? (New Outlook)
I'm using Outlook for Windows version 1.2025.109.100 (on behalf of another user). I'm reading some suggestions online that say you need to add the account to Outlook first before making it the default Send From. I'm also looking at the Help section in Outlook that directs you to change this in the Compose and Reply settings. However, it's not possible to sign into a mailbox that isn't a user. I thought you used to be able to 'sign into' a shared mailbox using your own account but that is not the case now (perhaps it never was?). What it seems like is that we instead need to convert "Accounting" to a User account, give it a license, then sign into it in Outlook. That's not a Shared Mailbox - that's a user mailbox. I don't want to create a point of weakness for a potential cyber-attack (which we've had several). I can't really set up MFA for this account that no one can maintain. And I really don't want to have to spend money on a license to do something just because one piece of software is incompatible. Having to repeatedly instruct people and then repeatedly remind them to change their FROM account is just bonkers. On Outlook for Mac, as long as you're in the Shared Mailbox, the default FROM is that mailbox. (but, don't get me started on how much better the Mac version of Outlook is than the Windows version - see: All Accounts)
Exchange SMTP Auth Fails with: 451 4.7.0 Temporary server error. Please try again later. PRX5
Office 365 refuses SMTP authentication with error: 451 4.7.0 Temporary server error. Please try again later. PRX5 This is when accessing External Send SMTP AUTH through OAUTH2 authentication. Initial authentication is successful (and is logged as so in Entra ID) but when trying to send send messages through authenticated SMTP, you get the above error. Working with multiple support reps, we looked through login logs and could not find any trace of the error in Entra ID. Support reps all blame the third party application. The issue is connected to a special use case, where a user has both the GLOBAL ADMIN role, as well as certain other admin roles. When you have a certain combination of those roles, for a selected user, OAUTH2 will fail, even though OAUTH2 for (apparently) ALL OTHER SERVICES - work without error! - ONLY SMTP Auth is affected. RESOLUTION: Keeping Global Admin while simply removing excess roles will almost immediately resolve the issue. This bug has been publicly noted as far back as August 2022, perhaps earlier. This needs to be fixed.
OOF to personal emails dropped at EOP relay
Issue: When an OutOfOffice recipient is gmail.com, outlook.com, msn.com ,etc, relay is dropped by EOP. Oof is delivered when recipient is an M365 tenant. Any other mail flows no issues to gmail and other personal addresses as well. It's only OOF to personal addresses. Env: Exch 2016 with EOP send/receive (hybrid manually, not hcw) We found 2 blog posts might be relevant, but these instructions did not resolve: https://techcommunity.microsoft.com/blog/Exchange/updated-requirements-for-smtp-relay-through-exchange-online/3851357 https://techcommunity.microsoft.com/blog/exchange/enhanced-filtering-for-connectors---improving-deliverability-and-minimizing-fals/4160483 This is what we see on the smtp protocol log: >,MAIL FROM:<> SIZE=7072, >,RCPT TO:<****@gmail.com> NOTIFY=NEVER, <,250 2.1.0 Sender OK, <,550 5.7.64 TenantAttribution; Relay Access Denied [*****.eurprd03.prod.outlook.com 2025-01-04T14:03:21.934Z *****], >,QUIT, ### We also looked into dkim, but finally found this line: By design, Exchange Online Protection uses the high risk delivery pool (HRDP) to send OOF replies, because OOF replies are lower-priority messages. https://learn.microsoft.com/en-us/exchange/troubleshoot/email-delivery/understand-troubleshoot-oof-replies#what-are-out-of-office-replies We feel this is not likely a connector or ceritifcate or onprem issue, rather something with HRDP and OOF in EOP. Could you confirm we are on the right track now? If not the Exchange Team can help please let me know who. Thanks
Move request falsely stuck
We are migrating mailboxes cross forest between two Exchange organizations and are having an issue with 3 of them. We were migrating these 3 mailboxes when the target Exchange server had the log disk filling-up, and move request seemed to be stuck. We extended the disk and the move actually completed, we check the get-moverequest for "non completed" and none was reported. We move the mailbox database, on the target DAG, between the two hosts and then, not sure if it's related, the get-moverequest reported three entries in "waitingforjobpickup" even if the migrationa has successfully completed, the mailbox is active on the destination and users are connecting without issue. How can we clear the status correctly or we just can delete the move request ? thanks SC
Exchange Online courses
Hello all, Since Microsoft ended the MS-203 certification and courses, there is no training available anymore. On the Micorosft Learn website there aren't courses about Exchange 365; only the 'manage complaince in Exchange 365'. Does any of you know if there will be a new training for Exchange 365 soon? Where do you find courses for Exchange 365 (and Defender for Office/Exchange). Kind regards, Arjan
Unable to change mailbox permissions
Hi, We have inherited a Hybrid Exchange environment. It consists of 1 on-prem Exchange Server (Version 15.0 (Build 1473.3)) and M365. All the mailboxes have been migrated to M365 and ADSync is present to replicate to M365. The issue we have is that even as a Global and Exchange admin in M365, we are unable to edit the permissions of any users mailbox. Doing this via the M365 admin centre just returns a message saying "Something Went Wrong." If we try it in Powershell we get a "User is not allowed to call" message. We are trying to understand if this is an issue with M365 or we are trying to make the permission change from the wrong location? In a hybrid environment where all mailboxes have been migrated, from where you should you make permission changes to a mailbox? Is there something else we are doing wrong here? Thanks DBMS Exchange SE 2025
Recently, I came to know that MS will next Exchange in Subscription Edition (https://techcommunity.microsoft.com/discussions/exchange_general/exchange-server-subscription-edition-arrives-in-summer-2025/4133577). The MS exchange 2025 will be the update of 2016 and 2019 version and 2016 and 2019 support will be the end of 2025. My query is new MS Exchange 2025 SE will be on-prem or cloud-based. If it is cloud-based, then the Active Director will be cloud-based, too. Can anyone clarify me those things.
User is unable to login to Mailbox
Hello experts, We are in Hybrid environment and one of the user which was recently re-enabled an AD account as the user is returned back to us, is unable to login to mailbox Steps we done Re-enabled the AD account and moved it to syncing OU and added license to enable mailbox I checked the recipient details in both on-prem and online On-prem results RecipientType : MailUser RecipientTypeDetails : RemoteUserMailbox Online results RecipientType : UserMailbox RecipientTypeDetails : UserMailbox What is the part that is missing here.Exchange Hybrid Wizard Error
Hi, At the final step of the Hybrid Wizard (Validating Hybrid Agent for Exchange usage), I am getting this error message. I've searched for this error and cannot find the correct fix. Thanks. The log files show his error: *ERROR* 10349 [Client=UX, Page=HybridConnectorInstall, Thread=15] The connection to the server 'fdde59f1-85fd-48b6-bbe4-0bf434e02b29.resource.mailboxmigration.his.msappproxy.net' could not be completed., The call to 'https://fdde59f1-85fd-48b6-bbe4-0bf434e02b29.resource.mailboxmigration.his.msappproxy.net/EWS/mrsproxy.svc' timed out. Error details: The request channel timed out attempting to send after 00:00:00.0077217. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. --> The HTTP request to 'https://fdde59f1-85fd-48b6-bbe4-0bf434e02b29.resource.mailboxmigration.his.msappproxy.net/EWS/mrsproxy.svc' has exceeded the allotted timeout of 00:00:00.0077217. The time allotted to this operation may have been a portion of a longer timeout., The request channel timed out attempting to send after 00:00:00.0077217. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout., The HTTP request to 'https://fdde59f1-85fd-48b6-bbe4-0bf434e02b29.resource.mailboxmigration.his.msappproxy.net/EWS/mrsproxy.svc' has exceeded the allotted timeout of 00:00:00.0077217. The time allotted to this operation may have been a portion of a longer timeout.Exchange Management Shell 2019
Hi All, We have a 4-node Exchange 2019 hybrid environment. On one of the nodes, we've noticed that connecting to the Exchange Management Shell takes an unusually long time, despite normal CPU utilization and all other services running smoothly. Has anyone experienced a similar issue or have any insights on potential causes and solutions?SMTP Issue - Exchange 2019
Hi All, I have an hybrid exchange environment (365 + 2019), and the onprem server is used for smtp relay only. An internal app uses this relay and send email as "email address removed for privacy reasons", and all works well except by an specific message-subject. This application can send all the emails with any subject, but if the subject is "Purchace Order to be approved" the relay fails. Checking logs, I could see that when the message has this mentioned subject then the field "sender-address" is always empty (return-path is ok). And, of course, SPF/DKIM fails and message is quarantined. All other message subjects contain the address in "sender-address". This could be an issue with my application or something related to smtp config? Source for fields analyzing: https://learn.microsoft.com/pt-br/exchange/mail-flow/transport-logs/message-tracking?view=exchserver-2019 Thanks and happy new year to all of you.
ERP system with MS 365 MFA user
Hello Expert Comm, I need to send emails from the ERP system, and all settings are done, but I need additional security to enable the MFA for the user that will use this service as I know the MFA must not be enabled for this setting and Security Default must NOT be enabled for the organization. So, if you have any workaround to enable the MFA for the account that will use the ERP system please let me know I have MS 365 emails Thanks, Kmohamed"Sender Address" vs "Sender mail from address"
I'm looking at an email that went to 365 hosted quarantine. On the surface, the email looks like it came from noreply at my company, but when I look at the details it shows as below. I'm confused by the difference between "Sender address" and "Sender mail from address" and "Return path"Shared Mailbox - Deactivate Calendar and Contacts
Hey everybody, I am struggeling to find the solution to my problem on the web and cannot believe that this should not be possible. We are using a few shared mailboxes (info@... / accounting@... ). Each shared mailbox comes with its own contact book which all show up in my contact tab in outlook. As we don't use the contacts and calenders of these shared mailboxes, how to I get rid of them? Same for the calendars. I don't need 6 empty calendars in the overview. It must be an option to turn them off entirely. Thanks and best Regards, FlorianDelegating permission to approve Quarantined Mobile Devices in Exchange Online
Hi all, I would appreciate some guidance. Today, we are configured to quarantine any mobile device that attempts to add their mailbox to their device. We have three administrators that can approve these devices. I'd like to delegate this responsibility to the person on our team who stages and deploys mobile devices without giving them full administrator access. Additionally, I am looking to grant access within the GUI, not the ability to run a PowerShell cmdlet. From this post on Reddit, I first attempted this process, but it did not seem to work. In the GUI, a user in the group I created cannot access the Mobile Devices page in the Exchange Admin Center. I then attempted this link to Microsoft documentation, but it doesn't seem to fit exactly. Granted, I don't have much experience with Exchange permissions. Any help, guidance, or direction you could point me in would be greatly appreciated. Thanks SteveSMTP Delivery to Mailbox fails
We have an exchange 2013 server in the Org and we added an exchange 2019 server on windows 2022. We got an issue where Exchange 2013 cannot forward email to exchange 2019 mailboxes due to SMTP error. In the log files we found we checked the TLS configuration on the exchange 2019 and TLS1.1 and 1.2 are enabled what can be the issue ?
Recent Blogs
- We wanted to provide an update on servicing Exchange Server 2019.Jan 16, 2025
- We know that some of our customers leverage Exchange transport rules to prepend subject line or insert the message body to show the email is from external senders. This approach has a few limitations...Jan 15, 2025
