Hotmail account blocked from sending (550 5.7.520 AS(4810)) and support replies bounce

Question

Hotmail account blocked from sending (550 5.7.520 AS(4810)) and support replies bounce

Jeremy Willuhn 0

My Hotmail account, [PII removed]@hotmail.ca, is blocked from sending email. Every message I send, to every recipient I've tried, bounces with:

550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)

It started on October 10, 2026. I use this account for my small business and send one-to-one client emails only, nothing bulk.

What I've tried:

Fails from Apple Mail and from Outlook on the web
Fails with and without a signature, and with a plain one-line text email
Fails to several different recipients, including a Gmail address
Sign-in activity is normal, there is no restriction banner, and my storage is not full
The Sign-in Helper and the Help pane did not lead me to a person (the support page would not complete sign-in for me)

The bounces come from Microsoft's own servers before delivery, for example:

Sat, 10 Oct 2026 20:29:58 +0000, reporting MTA LV3PR84MB3650.NAMPRD84.PROD.OUTLOOK.COM, origin SJ0PR84MB1580.NAMPRD84.PROD.OUTLOOK.COM

I submitted the Outlook.com sender support form twice and got the automated "not qualified for mitigation" reply both times. The form asks for an outbound IP, but I send through Microsoft's servers and don't have one, so the result doesn't apply to my situation. The request numbers are:

[PII removed]
[PII removed]

That automated email says to reply, without changing the subject line, to reach a live agent. I replied from two of my Hotmail accounts and both bounced. One of them returned: 550 5.7.64 TenantAttribution; Relay Access Denied, for ******@outlook.mail.microsoft.

Can someone from Microsoft review the outbound block on this account, or tell me how to reach a live agent for these cases? Thank you.

0 comments

1 answer

Your answer

Answer 1

Kai-H 28,425 Microsoft External Staff Moderator

(Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.)

Hi, Jeremy Willuhn

Thanks for explaining what you’ve already tried. Your tests point toward a service-side sending problem rather than Apple Mail or your signature; the IP-based Sender Support route is intended for problems sending to Outlook.com, not sending from your Hotmail account.

Here are some suggestions you can try:

Open Contact Microsoft Support using another personal Microsoft account, since sign-in on the support page failed with the affected account. Enter “Outlook.com sending blocked,” select Get Help, then Ask our Support Assistant and request for a live chat support session if offered, and choose the available chat option. Using another account to reach support is an established alternative, although chat availability varies.

Ask the agent to help route this to Outlook.com support for an outbound sending restriction review. Provide both existing request numbers, the full bounce reports, and the October 10 start date. Also explain that replies to their support address fail with 5.7.64, so email follow-up is currently unusable.

Please be advised that this is a user-to-user support forum. Moderators and contributors, including external Microsoft employees, are not allowed to directly interfere with Microsoft product features or access back-end systems. Our role is limited solely to providing technical guidance on reported incidents, requests, or ideas.

Jeremy Willuhn 0 Reputation points

2026-10-11T17:37:36.08+00:00
Update on my blocked Hotmail account, in case it helps others with the same error.

What happened: On October 10 my account was locked for suspected junk sending and, at the same time, all outgoing mail started bouncing with 550 5.7.520 AS(4810). I send one-to-one client emails only, and my Sent folder, inbox rules and sign-in activity are all mine.

What I tried:

I cleared the account lock at account.live.com with Microsoft's human check (press and hold) and reset my password. The sending block stayed, so these are two separate flags.

Plain-text tests from Outlook on the web and Apple Mail kept bouncing, with and without a signature.

The Sender Support form (IP-based) gave only an automated "not qualified for mitigation" reply, because it's meant for mail sent to Outlook.com, not for a blocked Hotmail account.

Replies to Microsoft's automated support emails bounced (550 5.7.64 Relay Access Denied).

I disabled my inbox rules at Tier 2's request. It made no difference.

What finally got a response: I signed in to support.microsoft.com with my other Microsoft account, as suggested here, and started a chat. A bot answered first and tried to send me to the Windows and Office queue. I told it the issue was on Outlook on the web and asked for Outlook.com support. It handed me off to an agent after a few screening questions, and the case was escalated to the Outlook Tier 2 team (case [PII removed]).

Tier 2's answer: the account was flagged by Microsoft's automated protection, outgoing mail was restricted, and they can't see the exact trigger. They advised updating my account profile and security info and not sending from the account for 24 to 48 hours, after which the restriction should lift on its own. If it doesn't, I can contact them again for an engineering review under the same case.

I'm waiting out the 24 to 48 hours and will test once on Tuesday, October 13. I'll post the result here.

Related requests: [PII removed]
Kai-H 28,425 Reputation points Microsoft External Staff Moderator

2026-10-12T07:33:04.03+00:00

Hi, Jeremy Willuhn

Thank you for the detailed update. I’m glad the alternate-account chat route got you through to Tier 2, although the sending issue is still unresolved.

Based on what Tier 2 told you, follow their case-specific advice rather than repeating the password reset, signature changes, or inbox-rule tests. The 24–48-hour window is their guidance for your account, not a guaranteed recovery time for everyone with AS(4810).

For your October 13 test, send one short, plain-text message from Outlook on the web. If it still bounces, save the new bounce report and contact support through the alternate account again. Reference your case number and ask for the engineering review Tier 2 offered. Include the test time and explain that the sending restriction remains after following their instructions.

Also remind them that replies to their automated support emails bounce, so you need a usable follow-up channel. Your update is helpful, particularly the distinction between restoring sign-in access and restoring outgoing mail.