Can i send Bulk emails around 150000 using smtp relay in office 365, is there any limitation

pavan kumar 371 Reputation points


Is there any limitation in sending an emails externally using office 365 smtp relay, we have an application that send emails to our external members with OTP, Transaction emails for day to day activity.

we are in a phase of migrating to office 365 soon, my manager likes to know is there any sending limit in office 365 per day using a smtp relay.


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  1. Robert Sparnaaij [MVP] 1,811 Reputation points MVP

    Yes there is a limit and no, your scenario is not allowed.

    See; Exchange Online limits - Sending limits

    It even contains an additional not about this;

    Exchange Online customers who need to send legitimate bulk commercial email (for example, customer newsletters) should use third-party providers that specialize in these services.

    3 people found this answer helpful.

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  1. Yuki Sun-MSFT 29,706 Reputation points

    Hi @pavan kumar ,

    Microsoft 365 has a Recipient rate limit of 10000 recipients per day which cannot be customized. So agree with Robert that you would need to look for some third party solutions for your scenario. For more information about the sending limits in Exchange Online, hopefully you can find the official link shared above by Robert helpful.

    By the way, if you found his post useful, it would be appreciated that you can accept his post as answer to close this up. This can make answer searching easier in this forum. If you have further concern on this, feel free to post back. Thanks!

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    1 person found this answer helpful.
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