I'm a Senior Network Engineer for another organization and won't go into our own email specifics.
However, what is likely an issue is that your company decided certain forms of email access in an "unsecure" local (ie, not inside of their own protected networks) that supporting POP3 or IMAP is not a good idea.
From a home user perspective, free accounts that offer POP3 or IMAP are easy to use. However, I don't touch them either.
Simple reason, POP3 and IMAP send your username/password in the clear. Meaning if I can intercept your communications traffic to your email server, I'll easily know your exact credentials and can then be "you". Many ISP's for example place their customers in the same subnet and dynamically assign an IP address out of that same subnet to those users. Search Google if you want more information, but criminals can and do this frequently (search for descriptions of BotNets for example). Outside of wired networks, you get into wireless. This is even waaaaaaaaay more easy. Especially since a large number of users use WEP, freeware software to crack this in less than 7 seconds has existed almost as long as the protocol even existed.
If you receive important personal, financial and other details by a POP3 or IMAP account, be warned. It's not a mater of "if" your identity would be stolen, but "when". Be sure to at least use POP3S or IMAP4S (SSL encrypted versions of these protocols). However, frequently you can't use the "Outlook Express" for these as Microsoft never updated it to use the correct ports for encrypted SMTP communications, hit or miss depending on the system the ISP uses.
As for Exchange, Microsoft has support for both Outlook Web Access and another service called "Outlook Anywhere" (formerly for those tech heads "RPC over HTTPS"). This allows for secure SSL communications to an Outlook 2003 (if manually configured) or Outlook 2007 (autodiscovery features now assist setup) client if the organization desires.
So if you have Outlook 2007, give it a try, the worst is that it won't work if they didn't enable the feature.
As for lost or deleted messages? Don't worry about it.... I'm sure if you ask, this can be recovered for you. As of December 2006, Federal Rules of Civil Procedure (that's the laws dealing with lawsuits, etc) have email as electronic evidence that needs to be provided quickly, see "e-discovery" for better details.
E-Discovery Amendments to the Federal Rules of Civil Procedure Go Into Effect Today : Electronic Discovery Law
So I'm sure that your company archives all the messages so as to quickly be able to search and provide for legal purposes. Truely big brother opertations may have statements in their corporate policy that they are routinely having HR search all emails for inappropriate use anyways.
Anyways, I do understand frustrations when it comes to the restrictions that many business are placing on email, but with all the cyber crime, SEC, HIPPA and other federal regulations they've got to comply with, I'm suprised many of us even still have email access "period".
As for all you home users, if you can't use SSL encrypted methods like POP3S or IMAP4S instead of just the plain versions, stick to using only the SSL encrypted (
https://) websites for email use. That "s" on the end indicates as a standard SSL use for web.