description copied from superuser.com:
http://superuser.com/questions/896780/outlook-2007-symantec-enterprise-vault-
saving-copy-of-email-does-not-maintain/896790

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At my employer we use Outlook 2007 + Symantec Enterprise Vault for archiving.
Messages older than 30 days are automatically archived, until 6 months and then
they are deleted if not marked with the category "Do Not Purge".

I need to add "Do Not Purge" to my email messages that I want to keep. A few
weeks ago it worked fine. If I did this on archived messages, it would tell me
it would have to create a copy of the email (I guess the archived items are
immutable), but that's no big deal, I would just delete the original and keep
the copy; the copy maintained the original received date/time.

Now when the email message is copied, the copy gets the date/time as of when
the copy is created, not the original email received date/time. Is there a way
to fix this on my client, or is this a server problem? I have no idea why this
is occurring and I have about a week left before I start to lose email
messages.

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I noticed that GpgOL was an installed Outlook plugin. Out of desperation I
uninstalled Gpg4win; the problem went away. (now copied email messages maintain
their received message date)

I have no idea what the actual problem is, and can't afford to spend any more
time trying to reproduce it. Just thought I'd file a bug report here.