Hidden Outlook Folders

[alpha69]

Is it possible to create a hidden or secret mail Folder in Outlook 03 so that correspondance can be stored away from prying eyes?

[Gertrude the Wombat]

Not sure what you're after here. The obvious starting point is not to give anyone else your password, and not to share across the network any part of your filing system that contains anything you want to keep secret.

And then keep the machine itself under lock and key, because the above doesn't, of course, keep out someone who (a) is sufficiently determined and (b) has physical access to the machine. But nothing will keep out such a person - if someone has physical access to your machine and they really want to they will be able to read anything. Look up "evil maid" attacks to see how pointless it is trying to secure a machine that someone can physically get their hands on.

So, as with any security question, you have to start by telling us your threat model - exactly what are you trying to guard against, and what do you consider an acceptable residual risk?

[Mornington Crescent]

This may not be exactly what you are looking for but:
You can protect your PST file such that when opening Outlook you will be required to give a password.

Select file-Data File Management- select Personal Folders - Settings - Change Password.

If you do not tick the remember box you will be asked for the password before Outlook opens. If you forget your password the information in the PST is lost.

[Bushfiva]

the information in the PST is lost.

Trivially recoverable, actually.

[Mornington Crescent]

I guess that you are right Bushfiva but that is the advice from MS.

[LH2]

If I may suggest, a more practical and effective solution would be to give your lover a different email address, one which you have created specifically for the purpose and only access via webmail (using Firefox's private mode).