Exchange STM file is roughly same size as EDB - Can I reduce this.

Hi there,

I have an exchange environment and their EDB is about 30gb in size, however their STM is about 27gb. This is the only site where I have seen this and I am wondering why it is so large and is there a way to reduce it. I did try an offline defrag but it made no difference.
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MesthaConnect With a Mentor Commented:
If the server is being abused, then you would tell, because there would be a lot of messages in the queues, and the server would be blacklisted.

You have to allow InfoStore maintenance to run and do cleanup, only then
 will offline defrag be able to reduce the size of .stm file.
The best way to do this is to defrag your mailbox using eseutil.  This is done by unmounting your mailbox then typing c:\Program Files\Exchsrvr\bin\eseutil.exe /d (path to database).

If that doesn't help take a look at the mailboxes in the exchange system manager and find what users are hogging up all the space.  Have them archive their email then run the defrag again.

This site also has additional information on how to defrag your mailbox store and other useful tools.

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mickinoz2005Author Commented:
Hi tenaj-207  as I said in my post I did an offline defrag and it made no difference.

Also mailbox size only affects the EDB to my knowledge not the STM.

This is why I am confused why the STM is so large.

The database sizes being approximately the same size is not that unusual. Due to the way the databases work it can be that way. STM contains SMTP email, basically email from outside, so if the environment receives a lot of messages from outside the network, which is perfectly possible, then the sizes can be the same.

On my own Exchange server, my STM file was much larger than the EDB file because about 99% of my email was from the internet (being the only user on the Exchange server was the cause of that).

Therefore I do not see anything wrong with the database size in that respect.

Yeah.... you're right about the mailbox size not effecting the EDB.

How big is your organization, how many mailboxes do you have?  If you have a lot of users and if you do a TON of emailing Simon could be right.

However, it sounds too high for an average company.  Here's a link that discusses what effects the size of STMs.

Creating a new store and moving the mailboxes to that store might help reduce the stm size, and you can do that without stopping email services.
mickinoz2005Author Commented:
Company is not large about 20 / 30 people if even not sure of the volume of emailing but to me it seems too high.

I did read somewhere (and as Mestha mentioned) if there is a lot of smtp mail you could have a big STM, is it possible that the server is being used for relay or spam.

We have about 100 networks that we manage and this is the only one I have seen that is this big.

tenaj-207Connect With a Mentor Commented:
To test if you're an open relay go to and click on the diagnostics link then put in your domain name and click "Test email server."

Simon wouldn't it move some of the information from the STM to the EDB if you created a new mailbox store and moved the mailboxes to that store? If nothing else that might help reduce the stm size because it would defrag the database (again), and you can do that without stopping email services.

How much free space to you have on the server?
mickinoz2005Author Commented:
We have about 3 times the size of the store free on the server so no issue with space.
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