Limits for mailboxes and messages

What are the sending limits for an account? buttonThe limits depend on whether you have just registered a new account, have been using your account for a while already or have a paid account.

Sending limits

Account typeRecipients per messageMessages per day
New account10 - 5010 - 50
Free user100300
Paid user100>300

The limits of a new account are gradually increased based upon their (proper) usage. This probation period usually takes a few days but can take up to 30 days. Periodically logging on to the website instead of just using the account via Outlook might help. Verifying your account (see below) and sticking to the Code of Conduct, is more important though.

The “messages per day” sending limit of messages sent on a smartphone via the POP3 and EAS protocol are lower but not directly specified.

These limits do not apply to linked external accounts (send-and-receive accounts and send-only accounts) for which you have specified a different SMTP server. In this case, the sending limits of that provider apply.

Mailbox size limit

Mailbox Size buttonThe mailbox size limit is 15GB but when it suddenly increases with several GB within a day (like when importing/uploading your pst-file into, you may need to wait a few days before more storage space actually becomes available.

When you also have a Microsoft 365 subscription tied to your account, then the mailbox size limit is 50GB.

Increasing the sending limit directly by verifying your account

Verify account buttonIf you find your account blocked because of hitting these limits, or you need to upgrade the limits of your paid account, via a Microsoft 365 subscription, you can use the SMS verification service of

This will increase your limit within some minutes after you complete the verification process.

Otherwise, contact support directly or post a question in the Answers Forum with your account name and the exact error you get when sending. That forum is moderated by Support and they can track your usage and modify the limits for you.

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