Mailbox full message

Question

I have Office 365 Business Premium subscription with 5 users each with a 50GB limit on email mailboxes, none of the mailboxes has more than 1.44GB in it. I am 

I am receiving messages saying my mail box is almost full at 954MB. Which mailbox is the message referring to and why is it full at less than 1GB?

I have automatic archiving on. How do I find out which mailbox it is and how do I increase the mailbox size to be 50GB?

Answer 1

Hi Karen,

As far as I know, you can get to the mailbox usage report in Office 365 admin center to learn the used storage of each Office 365 account.

Office 365 Reports in the Admin Center - Mailbox usage

Besides, the alert message would be sent to the mailbox which is almost full. Meanwhile, by default, the mailbox storage is the maximum size. And the alert message will be sent only when the remaining mailbox storage is less than 1 GB. For your reference, see Capacity alerts. Since you mentioned you have enabled Online Archive, you can go to Exchange admin center to check the remaining storage of Online Archive mailbox.

While if there's no mailbox reaching the maximum size, may I have a screenshot of your alert message? You can also send me the email in Private Message. I'd like to confirm if it's legitimate.

Regards,

Marvin

Answer 2

Hi Karen,

If you have further questions on this issue, feel free to let me know.

Regards,

Marvin

Answer 3

Thanks Marvin,

You pointed me in the right direction and the problem is now resolved.

Karen

Answer 4

Hi Karen,

Thank you for your information. From your email, the email was sent to a non Office 365 email account (you can check the "To:" field). Therefore, the alert message should be related with this external email account.

And since it's not sent to Office 365 account, it indicates the email shouldn't be sent from Office 365. Therefore, we cannot verify the legitimacy of this email. It could be sent from the other email provider and you may try to sign in this email account in the webmail to check if the mailbox storage is almost full. If not, the email could be spam, and you can just ignore it.

Regards,

Marvin