What you’re seeing
- Senders receive a non-delivery report with code 5.2.2 saying the recipient's mailbox is full.
- The user sees warnings that the mailbox is over its size limit, then stops receiving anything new.
- Eventually the user can't send messages either, and Outlook reports the mailbox has exceeded its quota.
- Other people at the company receive mail normally.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- The mailbox has reached its storage quota after years of accumulated mail and large attachments.
- The Recoverable Items area, which holds deleted mail for retention or litigation hold, has filled up and counts against limits.
- An archive mailbox was never enabled, or the policy that moves old mail into it is not running.
- A large number of oversized messages, such as scanned PDFs or photos, landed in a short period.
- The license or plan assigned to the user carries a smaller mailbox limit than expected.
Why it matters
A full mailbox turns away every new message, including from customers, vendors and banks, and the senders are told your employee cannot receive email. That looks careless and can cost orders, delay payments and cause missed deadlines. If the person is on a retention or legal hold, deleting mail to free space can also create compliance problems, so careless clean-up can do more damage than the bounce itself.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Will the people who emailed us know it bounced?
Yes, senders get a bounce notice, but they are not automatically re-sent once space is available. It is worth reaching out to anyone important who may have been turned away.
Do we have to delete old email to fix this?
Not necessarily. Archiving and reorganizing storage can often free space without throwing anything away, and we confirm any retention requirements first.