I would like to Defrag an Exchange 2003 mail store. Is it possible to take the mail store off-line without disrupting SMTP mail flow?

No, when you defrag the store is dismounted so no users in that DB store will be able to use email, send or receive. However, the emails will get queued until the store is mounted back.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Thanks, that's very helpful. So, other DB stores will not be disrupted correct?

no they wont, only the database you take offline will. Not sure why you want to do a offline defrag, I would create a new databse if possible (if not limited, i.e if youre using std edition) and move users across, this will be less impacting as you can move users acorss and you will have a clean database and will be reduced in size (physical) if this is your goal.Sukh

Hi, If you use Enterprise Edition I suggest you do as Sukh mentioned. Another advantage if you do like that is that you will not risk in lost message from the database. Perform a FULL backup of the Exchange Information store before you begin to do an offline defragment.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Agree with Sukh's suggestion.Gulab | MCITP: Exchange 2010-2007 | Skype: Gulab.Mallah | Blog: www.ExchangeRanger.Blogspot.com