Exchange Mailbox growing rapidly

Posted on 2013-01-09
Last Modified: 2013-01-30
We have a mailbox that in the past month has grown from >2gb to over 33gb.  The number of total items in the mailbox has grown normally.  It seems like one day a week the mailbox size increases and I get multiple transaction logs per minute. Looking at the mailbox I'm not finding large emails that would account for this size mailbox.

I've scanned for viruses and found nothing.  I also archived older emails which reduced the number of items in the mailbox but the size only shrank about 500mb.

Any ideas on what could be causing this mailbox to grow?
Question by:jwspeaker
  • 2
  • 2
  • 2
  • +2
LVL 23

Expert Comment

by:Thomas Grassi
ID: 38759300
What about attachments?

I had many users receive serveral attachments

We had to instruct them to detach the attachment from the email.

Just a thought
LVL 52

Expert Comment

by:Manpreet SIngh Khatra
ID: 38759339
Hope user didnt move some PST folder to Mailbox moving it so high and if you have some limit on the Mailbox for Send\receive how is it working ?

Can you please share some screenshot

- Rancy
LVL 10

Expert Comment

ID: 38759362
What versions of exchange /server o/s ?

Does the user have cached exchange mode if so is it the OST ( What size is it)

See if this helps

I have narrowed it down to a particular user. EXMON shows that this user is generating 50MB of log every minute.  There is nothing in the queues during this time though.  She also doesn't have any messages stuck in her outbox, and no large messages in her mailbox or archive folders.  It doesn't stop when she closes outlook but does stop when she logs off of her computer.  Logging back in and using Outlook doesn't appear to start it up again though.  I have installed wireshark and the traffic causing the problem is DCERPC traffic.  Looks like the client is requesting something and Exchange responds but it isn't clear as to what it is requesting.  I am going to rebuild her PC and upgrade her to Windows 7 and Office 2010.  She was on XP and Office 2003 before.  If this doesn't work I'm going to delete her AD account and mailbox.  Hopefully this will be enough.  I am also going to move her mailbox to a seperate database on a seperate volume so that it can't impact the rest of the organization.   I will also migrate all the other mailboxes to a new database just to ensure that everything is clean, and back to the size that it should be.
If anyone can explain what could have caused this, and why the database has grown from these DCERPC requests when the user is doing nothing with Outlook, I would be very interested.
In case anyone is curious, the details of the frames shown in wireshark look like this:
From Client to Exchange Server:
Request: call_id: 207918 opnum: 11 ctx_id:0
From Server back to client:
Response: call_id: 207918 opnum: 11 ctx_id:0
The numbers just keep incrementing and about 200 of these get generated every second.


Tuesday, March 22, 2011 10:57 PM


0 Points



I have rebuilt the user's machine, and so far the Exchange activity has gone back down to normal.    Not sure what was wrong with her PC but the issue is now resolved. I am migrating the mailboxes to a new database to bring the size back down to what it was before this issue started.

Expert Comment

ID: 38759384
drop the mailbox and associate her/his account with a new mailbox.  If the problem is with a single mailbox, you can then import what you need back.
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.


Accepted Solution

jwspeaker earned 0 total points
ID: 38760724
Apparently, there was 30+gb in the Sync Issues Conflicts Folder.  I think that was because 2 users use that mailbox and 1 had Cache Mode enabled and the other had it turned off.  I turned Cache Mode off on the user that had it on and cleared out the conflicts.  After I did that the mailbox shrunk down to the 400mb it was before.
LVL 52

Expert Comment

by:Manpreet SIngh Khatra
ID: 38762608
Thats good but strange as this should be available in Outlook folder size data ..... and i have never seen Conflicts folder with even in MB's

- Rancy
LVL 10

Expert Comment

ID: 38819211
What was causing it - so we can all learn something ?

Author Closing Comment

ID: 38834523
Because I figured it out on my own after I got none of the solutions to work.

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Scam emails are a huge burden for many businesses. Spotting one is not always easy. Follow our tips to identify if an email you receive is a scam.
MS Outlook is a world-class email client application that is mainly used for e-communication globally.  In this article, we will discuss the basic idea about MS Outlook, its advanced features, and types of MS Outlook File formats.
In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
how to add IIS SMTP to handle application/Scanner relays into office 365.

929 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now