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Are attachments stored in my Outlook PST? How can I remove them, if they are?


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.

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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

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.

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7 comments on “Are attachments stored in my Outlook PST? How can I remove them, if they are?”

  1. Leo,

    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

  2. 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

  3. 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?

  4. 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.

  5. Leo,
    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?


  6. 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.

  7. 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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