Microsoft Defender for Office 365 Blocks Prompt Injections
Microsoft Defender for Office 365 (MDO) can detect and quarantine email containing prompt injections. Shared mailboxes might need MDO Plan 2 licenses if they receive email from external domains. This requirement existed before MDO introduced Prompt Injection Protection, but the advent of the new capability is another reason to check mailbox licensing, especially if your tenant uses Copilot. We have a script to help! https://office365itpros.com/2026/08/04/microsoft-defender-prompt-injection/
Google Workspace sender stuck at SCL=5 to all Microsoft-hosted recipients
Sending email from a new domain via Google Workspace. All mail to Microsoft-hosted recipients (both Outlook.com consumer accounts and Microsoft 365 Exchange Online tenants) is being routed to junk. Authentication passes perfectly on every message. This appears to be a domain reputation cold-start issue and I am looking for guidance on how to resolve it without waiting 2-4 weeks. Affected recipients are all Microsoft-hosted recipients tested (Outlook.com consumer + Microsoft 365 Exchange Online tenants). Please help me!!! Confirmed via X-MS-Exchange-Organization-SCL: 5 and delivery header dest:J;OFR:SpamFilterAuthJ;RF:JunkEmail on all test emails including ones with normal subject lines and body text. Content makes zero difference to the score. What has already been done: SPF hardened from ~all to -all DMARC upgraded from p=none to p=quarantine IP confirmed not listed on Microsoft's delist portal (sender.office.com) Domain confirmed not listed on Spamhaus DBL or SURBL Domain registered with Google Postmaster Tools JMRP enrollment attempted — not available to Google Workspace senders as SNDS requires IP ownership Outlook.com Postmaster support request submitted
Techcommunity Follow email notification no longer working
Hello, Not sure if this is the right place to post this issue but I could not find another method to report this issue.. As an Exchange Admin in our invironment it's very usefull to stay up to date on the latest new posted in a variety of blogs on this website (Exchange Blog, M365 Blog, ...) This all went well until a few months ago where I started noticing I didn't receive any weekly updates anymore regarding new blogposts & tried to manually go check periodically, thinking it would be a temporary system. After investigation i've noticed that i'm not the only admin in our company that no longer receives these emails from mailto:email address removed for privacy reasons So I wonder if something bigger is up or if it's only my company being affected, not receiving these follow notifications anymore? Is there any other way that I should report this issue, to those managing this website so it can be investigated in detail if it's only us? Already tried to unfollow/delete follows in my profile - save - follow again, same on the respective blog pages, but this does not seem to change anything.
Moving Office 365 Mailboxes to IMAP Servers - What’s the Best Approach
I’ve recently been looking into scenarios where organizations need to move mailboxes from Microsoft 365 to IMAP based email servers, and I noticed this is still a common requirement in many migrations. In most cases, the challenge is not just moving emails, but making sure everything like folder structure, old emails, and user data stays intact without creating too much disruption for users. From what I’ve seen, doing this manually can get very complex, especially when there are multiple mailboxes or large data volumes involved. That’s where migration tools usually come into the picture. Most tools simplify things by handling: 1. Secure connection to Microsoft 365 accounts 2. Bulk mailbox migration 3. Preserving folder hierarchy 4. Reducing downtime during the move 5. Avoiding duplicate data issues One thing I’ve noticed is that running a small pilot migration first always helps. It gives a clear idea of how the actual migration will behave before moving all users. Has anyone here worked on Office 365 to IMAP migration at scale? Would be good to know what approaches or tools worked best in your case and what challenges you faced during the process.Office 365 Mailbox Export to PST - Third Party Tools: What’s Your Experience?
Exporting Office 365 mailboxes to PST is still a common requirement in many Microsoft 365 environments, especially for backup, compliance, and migration scenarios. While Microsoft offers native options like Purview eDiscovery and Outlook export, many administrators also consider third-party tools when dealing with large mailboxes or bulk export requirements. In real-world scenarios, factors like speed, ease of use, permission handling, and consistency of exported data often influence the choice of tool. Some teams prefer native methods for compliance control, while others explore third-party solutions to simplify large-scale or repeated export tasks. For those working with Microsoft 365, what has your experience been with third-party PST export tools? Have they helped in your environment, or do you still rely mainly on Microsoft’s native options?
Prevent Microsoft 365 meeting invites from automatically appearing in users’ calendars
Hi All, We are trying to prevent Microsoft 365 meeting invites from automatically appearing in users’ calendars as Tentative until the user explicitly accepts the invite. Setting for Outlook Classic, New Outlook and Windows or Outlook Web. Need Microsoft recommendation on this one.Microsoft Issues Updated Guidance for Defender for Office 365 Licensing
Some inconsistencies in the MDO P2 service description and licensing terms exposed a need for tenants to license every user and shared mailboxes. Microsoft has changed the service description and licensing terms to make them simpler. Mailboxes still need MDO licenses, but only if they benefit from MDO protection, including MDO P2 if that’s what they use. Tenant admins have some extra work to do to deploy policies. All explained here. https://office365itpros.com/2025/10/31/mdo-p2-licensing/Disable Direct Send in Exchange Online to Mitigate Ongoing Phishing Threats
Direct Send allows devices and applications to send unauthenticated emails over port 25 directly to Exchange Online. While this may support legacy devices like printers or scanners, it also opens the door for threat actors to deliver spoofed emails without authentication. These messages often appear to come from trusted internal sources, making them especially dangerous. To reduce your organization’s exposure to this threat, it's strongly recommended to disable Direct Send using Microsoft’s newly introduced RejectDirectSend setting. You can quickly enable this setting using PowerShell: Connect-ExchangeOnline Set-OrganizationConfig -RejectDirectSend $true If you still have devices or applications that need to send emails, use authenticated SMTP submission or set up connector-based routing with certificate or IP restrictions.
