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

Question

Hi,

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.

Thanks
Pavan.

Answer 1

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.

Answer 2

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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Answer 3

Sending 150,000 emails using regular SMTP like Office 365 isn’t recommended. It's better to use bulk email services like SMTpget, iDealSMTP, Mailgun, or Amazon SES that are made for large email campaigns.