Why are spam emails that are blocked still getting through on my iPhone version of Outlook but blocked on desktop

On Outlook/Exchange accounts, spam blocking is done on the server, not per device. Classic Outlook on desktop and Outlook for iOS are just different clients showing what the server has decided to treat as junk. The behavior described usually comes from a mix of:

• Different junk/block settings between server and client
• Senders changing addresses/domains so simple address-based blocks don’t catch them

Use server-side junk settings and rules so all devices (including iPhone) behave consistently.

1. Make sure blocking is configured on the mailbox (server), not only on the phone

If using Outlook.com or Microsoft 365 mail:

1. In a browser, sign in to Outlook on the web.
2. Select Settings (gear icon) > Mail > Junk email.
3. Under Blocked senders and domains, add:
   • The full addresses that keep spamming (for example, someone@example.com).
   • Or the domains (for example, @gameswithoutbets.com, gameswithoutbets.com, @championspub.nl, etc.) instead of just individual addresses.
4. Select OK, then Save.

Messages from addresses or domains in Blocked senders and domains are always treated as junk and moved to the Junk Email folder for all clients, including Outlook for iOS.

Reference behavior:

• “Messages received from any email address or domain in your blocked senders list are sent directly to your Junk Email folder.”
• “Messages from addresses or domain names in the Blocked Senders List are always treated as junk. Outlook moves any detected incoming message from senders in the Blocked Senders List to the Junk E-mail folder, regardless of the content of the message.”

2. Use Safe Senders so important Costco mail is not blocked

To avoid blocking legitimate Costco mail while blocking spam using the same brand name:

1. In Outlook on the web, go to Settings > Mail > Junk email.
2. Under Safe senders and domains, add the real Costco sender addresses or domains you trust.
3. Select OK, then Save.

Messages from addresses or domains on the Safe senders and domains list will not be moved to Junk.

3. Tighten junk filtering and use rules for pattern-based spam

In Outlook on the web:

1. Go to Settings > Mail > Block or allow.
2. Ensure Automatically filter junk email is selected so server-side junk filtering is active.
3. Optionally, use:
   • Blocked Senders for domains like gameswithoutbets.com, championspub.nl, studentcsprojects.com, vipticketsuk.com.
   • Safe Senders and Recipients for trusted contacts and services.

For senders that constantly change addresses but share common wording, create rules instead of blocking individual addresses:

• In Outlook.com / Outlook on the web, create an Inbox rule that looks for specific phrases in the subject/body and moves those messages to Junk Email or Deleted Items. See “Manage email messages by using rules in Outlook” for details.

This catches “Costco Special Offer”–style spam even when the domain changes, without blocking all mail that simply contains the word “Costco.”

4. Why desktop and iPhone appear different

• Classic Outlook on desktop shows the result of server-side junk filtering plus its own local Junk Email Filter and Blocked Senders list.
• Outlook for iOS relies primarily on what the server has already classified. If blocking is only configured in the desktop client’s local lists, those decisions may not apply on the server, so the iPhone can still show the messages in Inbox.

Ensuring all key blocks and safe senders are configured in Outlook on the web (server-side) makes behavior consistent across desktop and iPhone.

References:

• Filter junk email and spam in Outlook
• Block a mail sender in Outlook
• Block or unblock senders in Outlook
• Block or allow (junk email settings)
• Receiving email from blocked senders in Outlook.com