Category: phishing

  • Blocking onmicrosoft.com Emails in Exchange Online Protection

    Blocking onmicrosoft.com Emails in Exchange Online Protection

    There is a considerable uptick in emails from the default domain in Microsoft 365 tenants. These emails come from senders @ tenant.onmicrosoft.com and are not your tenant. Microsoft recently announced recipient external sender limits to reduce this, as the default is 10,000 recipients per day, but will get an additional restriction of no more than…

  • More Frequent Quarantine Notifications in Exchange Online Protection

    More Frequent Quarantine Notifications in Exchange Online Protection

    Available from the end of April 2023 there is now an option to increase the notification interval to end users about items in the quarantine. The Microsoft 365 Quarantine is at https://security.microsoft.com/quarantine and though this is a good link to add corporate intranets, its also a useful one for users to remember and bookmark. Up…

  • Improving Exchange Online Email Deliverability Through Third Party Filtering Services – Trusted ARC Sealer

    When you receive emails into Exchange Online and you filter the external messages before arrival with a third party filter such as Mimecast, Proofpoint or others, then you can have DMARC failures that result in messages being junked or quarantined in Exchange Online. Trusted ARC Sealer is a feature of Exchange Online to allow you…

  • Allowing “Phish” Training Emails in Exchange Online

    With the introduction of “Secure by Default” in Exchange Online, where you used to add IPs and other settings such as allow-lists to allow your phish training emails to get through to your users this will no longer work, and shortly it will no longer work to bypass the Exchange Online filters using mail flow…

  • Exchange Online Warning On Receipt Of New Email Sender

    Exchange Online Warning On Receipt Of New Email Sender

    Released recently to no fanfare at all, Microsoft now has a SafetyTip that appears if you receive email from a first time recipient. Most often phish emails will come from an address you have never received email from before, and sometimes this email will try to impersonate people you communicate with or are internal to…

  • Enable Report Message Add-In For Office 365

    There is a new add-in available for Outlook and OWA in Office 365 that can simplify spam and phishing reporting to Microsoft for content in your mailbox. I recommend rolling this add-in out to everyone in your Office 365 tenant and for Office 365 consultants to add this as part of the default steps in…