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The ability to send other files as attachments to email is very useful, but also results in bloated email folders and in Outlook's case, PST files.

I started using Outlook in May 2006. I have a big pst file, about 3.6 gigabytes. I archived and am compacting, so that should work. My question is about attachments, are they part of the pst file size? When I get an attachment I want, I click on save as and save it outside Outlook. However, does the attachment then still remain in Outlook? Is there a way to delete attachments while still keep the body of the emails?

Attachments are most definitely part of the PST file size. In fact, I'd hazard a guess that attachments are the number one cause of PSTs getting as big as they do.

And 3.6gig is a pretty big PST.

I have some cautions for you, and some steps you can take.

All attachments and embedded graphics and formatting are stored as part of the individual email within which they happen to appear. So if you get a 5 word email message with a 100 megabyte attachment, that's a single mail message that's over 100 megabytes in size. Actually, because of the way that an attachment must be encoded as text, that 100 megabyte file might well take up 120 megabytes or more of space in the email message, and as a result in your PST.

Saving an attachment doesn't remove it from the message, and hence does not remove it from the PST.

When you save an attachment, all you're doing is:

"You can delete attachments from the email you've received, and therefore from your PST."
  • converting the attached file from its textual email encoding back to its original form

  • saving that converted form to a new file

You haven't changed the email at all. All you've done is made and saved a copy of the attachment.

Which, by the way, is also what happens if you double click to run or execute the attachment - it's decoded, a copy is written to disk, and that copy is then run or otherwise acted on.

You can delete attachments from the email you've received, and therefore from your PST.

Since the attachment is part of the email message, what you'll do is modify the message. Open up the message containing the attachment you want to remove, right click on the attachment, and click on Remove. That's all there is to it.

After you've removed a few attachments, you won't see the PST get smaller right away. You'll either need to wait to let Outlook compact the PST itself, or force compaction manually.

Now, I can't let that "3.6gig" go without comment. That's a huge PST. I hope you're using the latest version of Outlook - or rather the later version of the PST file format - since older versions will have problems when PST's exceed 2gig. Even if you are using the proper version, that big a PST makes me very, very nervous. I would absolutely make sure that it's being backed up regularly, and I'd seriously consider breaking it into several smaller PSTs.

Article C2947 - February 28, 2007 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Geoff Walker
March 3, 2007 2:13 PM


Your reader asked "Is there a way to delete the attachments while still keeping the body of the email? Your answer is applicable to new emails, but what about the tens of thousands of emails that are already in the PST? The answer is an Outlook attachment management utility. There are programs that can extract (remove) all the attached files from an existing PST file and save them separately; there are programs that can automatically remove and save the attachment as new emails come in. In my opinion, the two best sources of such utilities are and

Best Regards,
Geoff Walker

August 8, 2007 6:32 AM

I have lots of e-mails with zip files in Outlook 2003 - I've tried right clicking and choosing remove, but remove is greyed out. Is there any reason for this i.e. a security setting, as my PST is getting to the unreasonable size stage and I'd like to do something about it, preferably with 3rd party programs. Thanks, Emma

Joan Edington
August 26, 2007 6:44 AM

I agree with the idea of deleting attachments to keep the PST small. However, what I would really like is that, when the attachment is deleted, a comment is still retained in the e-mail of the file name that had been attached originally. Just like it does when you reply to an e-mail in fact. Is this possible?

September 18, 2008 9:39 PM

Hi ,
I am using my outlook from last 4 years I have so many pst I want to get only my all email from pst . can u tell me about it if any tool is available in online.

January 24, 2010 11:35 PM

I know the major source of my attachments is a particular sender. I even have a sub folder for that sender. How do I split my pst to extract mails from the particular sender?


Elaine Wagoner
February 17, 2010 10:50 AM

Check out this app from Nirsoft.

Run this app, you can choose the attachments to delete. Also, after deleting you should 'compact' your data PST file, then you should see a smaller file size.

I periodically delete ALL of the attachments that are in my 'sent' folder. The file is already on my hard drive-there's no need to keep it with my Outlook.

December 15, 2011 7:27 PM

Hears an easy way to remove overparticular emails without using third party tools. create search by right clinking on the search folder in your pst in outlook. after the search is complete(you can do other things will it is searching like go to your inbox and send emails) move them to anothere pst or the.

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