How can retrieve compacted email messages?

Do you mean attachments that are "zipped'?

The entire email would disappear.

Im a little confused by this thread.
I use Microsoft Outlook email everyday at work and never saw an email disappear.
Or I'm not understanding your post.

Is it a normal standard email that disappeared?

And are you using this at home or work?

Oh I see. I found an article which may help:
http://email.about.com/od/outlookexpresstroubles/qt/et_compact_oe.htm

Do you have XP with Service packs 2 installed? Best to turn off the Compact feature.