It does this based on the modified date and not the received date. See;
http://www.howto-outlook.com/faq/archivenotworking.htm
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Robert Sparnaaij [MVP-Outlook]
Coauthor, Configuring Microsoft Outlook 2003
http://www.howto-outlook.com/
Outlook FAQ, HowTo, Downloads, Add-Ins and more
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"Phippsy" <(E-Mail Removed)> wrote in message
news:CF3E4358-FD76-4594-BE5D-(E-Mail Removed)...
> Where it says clean out items older than 1 month for example. How does it
> define the month. I have done it with 2 emails received on the same day
> and
> it will only archive one of them.
>
> thanks