How to fix email send out erro 550 5.7.236

Question

How to fix email send out erro 550 5.7.236

Loh 10

Domain user : [Moderator note: personal info removed] .com

Send out error

Remote server returned "550 5.7.236 Your message can't be sent because your tenant has exceeded its daily limit for

Ken Ebert 0 Reputation points

2026-10-09T20:23:37.1366667+00:00

This does not seem logical at all. By operating this way, Microsoft is pissing off its (formerly) loyal single-member small business customers like independent consultants and losing out on free Microsoft advertising as Microsoft will no longer be in the domain name. Just crazy. I wish I would have known this beforehand otherwise I would not have chosen Microsoft for setting up my small business email account. I will be sure to broadcast my displeasure about Microsoft to others over this restriction and how it really hurts small businesses across America. Just insane. I also will not plan on giving any more money to Microsoft, I will ensure I will buy my non-Microsoft domain directly via domain providers and use my onMicrosoft alias as little as possible so Microsoft doesn’t get seen in the light of my business. What a nightmare. Hopefully Microsoft will take positive action on this in future.

5 answers

Your answer

Ken Ebert 0 Reputation points

2026-10-09T20:23:37.1366667+00:00

This does not seem logical at all. By operating this way, Microsoft is pissing off its (formerly) loyal single-member small business customers like independent consultants and losing out on free Microsoft advertising as Microsoft will no longer be in the domain name. Just crazy. I wish I would have known this beforehand otherwise I would not have chosen Microsoft for setting up my small business email account. I will be sure to broadcast my displeasure about Microsoft to others over this restriction and how it really hurts small businesses across America. Just insane. I also will not plan on giving any more money to Microsoft, I will ensure I will buy my non-Microsoft domain directly via domain providers and use my onMicrosoft alias as little as possible so Microsoft doesn’t get seen in the light of my business. What a nightmare. Hopefully Microsoft will take positive action on this in future.

Answer 1

Hin-V 16,830 Microsoft External Staff Moderator

Hi @Loh

Thank you for posting your question in Microsoft Q&A.

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.

As my research, the error code "550 5.7.236" is thrown when emails are being sent from an onmicrosoft.com domain, and the tenant has reached Microsoft’s external sending limit. The outbound mail sent from default onmicrosoft.com (MOERA) domains is throttled to 100 external messages per 24‑hour rolling window. Once that limit is reached, Exchange Online blocks further messages and returns this error.

User's image

Reference: Email non-delivery report (NDR) and SMTP errors in Exchange Online - Exchange | Microsoft Learn

As AI suggestion, you could try to:

Wait for the 24‑hour rolling window to reset

Once your tenant falls back below the limit, sending will resume automatically. This usually resolves itself within a few hours depending on when emails were sent.

Using a custom domain

To prevent this issue from recurring, you may want to consider implementing a more permanent solution by shifting your outbound email traffic to a custom domain. Microsoft enforces strict limits on the default onmicrosoft.com domain, capping it at 100 external emails per 24‑hour rolling window, and strongly recommends using a custom domain to avoid throttling and improve overall email deliverability.

User's image

You can refer via:

Limiting Onmicrosoft Domain Usage for Sending Emails | Microsoft Community Hub

I hope this helps.

Please feel free to correct me if I misunderstood your request. If you have any additional concerns, feel free to comment below. I would be more than happy to assist.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in [our documentation] to enable e-mail notifications if you want to receive the related email notification for this thread.

Hin-V 16,830 Reputation points Microsoft External Staff Moderator

2026-02-06T07:49:56.95+00:00

Hi @Loh

Good day and I hope you're doing well. I just wanted to check in and see if there is any update from you.

If you have any questions, please feel free to reach out. I’ll be happy to assist further.

Looking forward to your update.
LinClaudia 0 Reputation points

2026-03-10T02:59:59.3533333+00:00

I can't beleive that Microsoft is so greedy to ask for more money. I used .onmicrosoft.com for one year, nothing happen. We never send more than 100 emails per day from each account, Suddenly we have to pay for our company domain. It's so greedy policy.
Hin-V 16,830 Reputation points Microsoft External Staff Moderator

2026-03-11T07:59:02.4166667+00:00

Hi @LinClaudia

Thanks for reaching out and sharing your concerns.

I understand this might cause inconvenience to your current workflow. However, this could depend on how Microsoft centralizes its services and how they align with your organization’s needs and priorities.

Appreciate your patience and understanding.
Ken Ebert 0 Reputation points

2026-10-09T20:25:27.8166667+00:00

This does not seem logical at all. By operating this way, Microsoft is pissing off its (formerly) loyal single-member small business customers like independent consultants and losing out on free Microsoft advertising as Microsoft will no longer be in the domain name. Just crazy. I wish I would have known this beforehand otherwise I would not have chosen Microsoft for setting up my small business email account. I will be sure to broadcast my displeasure about Microsoft to others over this restriction and how it really hurts small businesses across America. Just insane. I also will not plan on giving any more money to Microsoft, I will ensure I will buy my non-Microsoft domain directly via domain providers and use my onMicrosoft alias as little as possible so Microsoft doesn’t get seen in the light of my business. What a nightmare. Hopefully Microsoft will take positive action on this in future.

Answer 2

This does not seem logical at all. By operating this way, Microsoft is pissing off its (formerly) loyal single-member small business customers like independent consultants and losing out on free Microsoft advertising as Microsoft will no longer be in the domain name. Just crazy. I wish I would have known this beforehand otherwise I would not have chosen Microsoft for setting up my small business email account. I will be sure to broadcast my displeasure about Microsoft to others over this restriction and how it really hurts small businesses across America. Just insane. I also will not plan on giving any more money to Microsoft, I will ensure I will buy my non-Microsoft domain directly via domain providers and use my onMicrosoft alias as little as possible so Microsoft doesn’t get seen in the light of my business. What a nightmare. Hopefully Microsoft will take positive action on this in future.

Answer 3

Nicoleta Ursache 0

Hi!

I experienced the same error, but in my case the external recipient limit was NOT exceeded.

The issue was caused by a backup/storage system (QNAP/Altaro) sending email notifications every 1–2 seconds to a mailbox in the tenant.

This high-frequency sending appears to have triggered throttling/abuse protection, which blocked or delayed mail flow, even though the daily recipient quota was not reached.

Hin-V 16,830 Reputation points Microsoft External Staff Moderator

2026-04-09T22:08:13.3533333+00:00

Hi @Nicoleta Ursache

Thank you for reaching out and sharing your concerns.

To help us support you more efficiently, please create a new thread on the forum and include the full details of your issue.

When posting, please sure to include:

A clear description of the symptoms you are experiencing.

Any recent changes made to your server or environment.

This information will allow our team to better understand the situation and provide the most accurate guidance.

Warm regards.

Answer 4

EmilyS726 271.9K Independent Advisor

This means your tenant has reached the daily send limit, you have to wait 24 hours.

What domain do you use? Do you use your own custom domain, or do you use Microsoft's onmicrosoft.com domain?

0 comments

Answer 5

The error code 550 5.7.236 indicates that your message cannot be sent because your tenant has exceeded its daily limit for sending emails to external recipients from your organization's onmicrosoft.com domain. This limit is enforced to prevent abuse and is set to 100 external recipients within a 24-hour rolling window.

To resolve this issue, consider the following steps:

Wait for the Limit to Reset: The external recipient limit is tracked over a 24-hour rolling window. You can resume sending messages once the count for the most recent 24-hour period falls below the limit.
Use a Custom Domain: If you frequently need to send emails to external recipients, consider purchasing and migrating to a custom domain. This will help you avoid the limitations imposed on the onmicrosoft.com domain.
Monitor Your Sending Patterns: Keep track of how many external recipients you are emailing to avoid hitting the limit in the future.

If you continue to experience issues, you may need to contact Microsoft support for further assistance.