How to stop annoying SPAM in Hotmail calendar

Check the Hotmail calendar in Outlook.com first, then remove the spam at the server if it appears there or resynchronize the Outlook.com account if it appears only on the iPhone.

1. Determine where the events exist

Sign in to Outlook.com in a browser, open Calendar, and search for one of the exact spam titles or dates.

• Events appear in Outlook.com: They are stored in the Hotmail calendar. Continue with section 2.
• Events appear only on the iPhone: Skip to section 3. Outlook.com calendar data synchronizes between the server and connected devices, so an iPhone-only result points to its local calendar view or synchronization state.^1^

2. If the events also appear in Outlook.com

Do not keep selecting Decline. Outlook.com does not offer a “decline without sending” option, so declining attempts to contact the organizer; that also explains why an undeliverable or invalid organizer can produce “Your response … cannot be sent.”^2^

Instead:

1. In Outlook.com Mail, search for the matching invitation by its title or date.
2. Select it without opening links or attachments.
3. Choose Report → Report phishing. This reports the sender, removes the message from the Inbox, and contributes to Microsoft’s filtering.^3^
4. In Calendar, open the corresponding event and use Delete if that option is available, rather than Decline. The closely matched Outlook/iPhone guidance states that Delete removes the event without sending a response.^4^
5. Refresh Outlook.com and verify that the event remains gone. Then allow time for the deletion to synchronize to the iPhone.

Blocking a sender may help with repeated mail from one address, but it is unlikely to stop campaigns that continually change sender addresses. Reporting a message as phishing also does not automatically add its sender to the blocked-senders list.^3^

3. If the events exist only on the iPhone

Since you have already ruled out suspicious subscribed calendars, do not repeat that check. Rebuild the iPhone’s Outlook.com calendar synchronization:

1. Open Settings → Apps → Mail → Mail Accounts.
2. Select the Hotmail/Outlook.com account.
3. Turn Calendars off, wait briefly, and turn it back on.
4. Reopen Calendar and search for one of the spam events.

If they remain:

1. Return to Settings → Apps → Mail → Mail Accounts → [Hotmail account].
2. Select Delete Account. This removes the account’s synchronized data from that iPhone, so ensure the required mail, contacts, and legitimate calendar items are visible in Outlook.com first.
3. Add the account again and choose Outlook.com, not IMAP. Microsoft documents deleting and re-adding the account as the next iOS synchronization repair step.^5^
4. Confirm that Calendars is enabled and check whether the spam entries return.

If they return immediately after re-adding the account, they are being supplied by the Outlook.com mailbox even if browser search did not locate them. Report the behavior from new Outlook using Help → Feedback → Report a problem, including screenshots, dates, and the exact failed-response message.^6^

For personal Outlook.com/Hotmail accounts, current Microsoft Q&A guidance describes recurring spam calendar invitations as an ongoing issue without a complete user-side prevention setting.^7^

References

1. Sync basics - what you can and cannot sync
2. how to decline a meeting without sending a response - Microsoft Q&A
3. Phishing and suspicious behavior in Outlook | Microsoft Support
4. spoofed email and spam events - Microsoft Q&A
5. [iOS Mail](https://support.microsoft.com/outlook/can-t-sync-calendar-and-contacts-with-my-phone-or-tablet)
6. How do I delete spam meeting invitations in Outlook without "declining"? (New Outlook) - Microsoft Q&A
7. Spam invitations in my calendar - Microsoft Q&A