Outlook suddenly delaying or not delivering emails to me

Question

HI,

All of sudden, some emails are delivered after more than 10 hours or not at all from a sender who is in the trusted list. I checked all settings - nothing. It didn't even accept my email from my personal gmail account.

Yet, all stupid promotional emails are let in.

Can someone, please, give a series of steps on how to find a solution to this?

Thank you!

Answer 1

Hello

I think there's something going on Microsoft's end right now. I am seeing many people reporting that they cannot receive emails from Yahoo or Gmail users. You are not the only one. Earlier this week it happened with iCloud users, but it finally recovered. Hopefully this is a similar situation. There's no official announcement on Microsoft side at the moment.

Answer 2

Use the following checks and steps in order, focusing on Outlook.com / Outlook on the web.

1. Check blocked senders and rules

• Sign in to Outlook.com or Outlook on the web.
• Go to Settings > Mail (or Options).
• In the left pane, open Junk email / Blocked senders or Block and allow.
• Verify the sender and personal Gmail address are not listed under Blocked senders or blocked domains.
• If they appear, select the address or domain and remove it.
• Also review any rules under Mail > Rules to ensure there is no rule that moves, delays, or deletes messages from those senders.

2. Verify the sender is not being blocked upstream

• If messages from a specific sender never arrive, ask that sender to confirm they are not receiving non‑delivery reports (NDRs) and that their messages to other recipients work.
• If their messages to Outlook.com specifically are failing, ask them to contact Microsoft support via postmaster.live.com so their sending IP/domain can be checked.

3. Check for delayed delivery rules in Outlook (if using classic Outlook with Outlook.com) If Outlook.com is also used via classic Outlook on Windows:

• In Outlook, select Rules > Manage Rules & Alerts.
• On E-mail Rules, select each rule and read the Rule description.
• Look for any rule that includes “defer delivery by # minutes”.
• Double‑click such a rule and clear the defer delivery by a number of minutes action so messages are not intentionally delayed.

4. Check for add‑ins delaying send (classic Outlook) If Outlook.com is connected to classic Outlook and delays are seen only there:

• Temporarily use Outlook on the web or the new Outlook to send/receive.
• In classic Outlook, disable any web add‑ins that perform actions On Send. These can delay messages while they process the send request.
• After disabling the problematic add‑in, test sending again.

5. Test with web only

• Sign out of all mail clients.
• Sign in directly to Outlook.com in a browser.
• Send a test from the personal Gmail account and from the trusted sender.
• If messages arrive on the web quickly, but not in a desktop client, the issue is likely with the client (rules, add‑ins, or profile) rather than Outlook.com itself.

If, after these checks, messages from the specific sender still do not arrive or are heavily delayed only for Outlook.com, the sender’s mail system needs to work with Microsoft via postmaster.live.com to investigate delivery and filtering on the service side.

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References:

• Where are my email messages or calendar events in Mail and Calendar for Windows 10?
• Email messages remain in the Outbox because of Deferred Delivery rule
• Outlook email is delayed while a web add-in is working on the send request