Defender for Office 365
10 articles tagged Defender for Office 365.
A Microsoft 365 tenant security baseline you can apply in a day
Harden a new or existing Microsoft 365 tenant in one working day: emergency access, admin roles, MFA and legacy auth, app consent, email protection, external forwarding, audit logging and Secure Score.
Configure ARC trusted sealers and Enhanced Filtering for an email gateway
Stop SPF, DKIM and DMARC failures on mail that reaches Exchange Online through a third-party gateway by combining Enhanced Filtering for Connectors and ARC.
Defender for Office 365 anti-phishing: stop CEO fraud and lookalike domains
Configure impersonation, mailbox intelligence and spoof protection in Defender for Office 365 anti-phishing policies to stop executive and lookalike-domain phishing.
Find and remove malicious inbox and forwarding rules after a BEC
After a compromised mailbox, find hidden inbox rules, SMTP forwarding and delegate access in Exchange Online, remove them safely and block external auto-forwarding so the attacker can't come back.
Fix 550 5.1.8 Access denied, bad outbound sender in Exchange Online
Why Exchange Online blocks a user with 550 5.1.8, how to secure the account first, and how to remove it from Restricted entities in the Defender portal or with Remove-BlockedSenderAddress.
Fix email false positives with submissions and the Tenant Allow/Block List
Release wrongly blocked email in Microsoft 365 the safe way: admin submissions, expiring Tenant Allow/Block List allow entries, and the allow methods to avoid.
Fix Microsoft 365 email going to Junk by reading SFV, CAT and compauth
Work out why Exchange Online delivered a message to Junk Email from its anti-spam headers, then apply the fix that matches the component that filtered it.
Quarantine policies in Defender for Office 365: release, notify, review
Create quarantine policies that decide who can release quarantined email, turn on quarantine notifications, and handle user release requests as an admin.
Safe Links and Safe Attachments in Defender for Office 365, explained
How Safe Links and Safe Attachments policies protect email, Teams and Office files, how Built-in protection differs from Standard and Strict, and how to configure, test and troubleshoot them.
Tenant Allow/Block List: allow spoofed senders and block domains safely
Use the Tenant Allow/Block List in Microsoft Defender to allow legitimate spoofed senders with domain pairs and block domains without side effects.