The IBM/Lotus Notes client provides very powerful search tools for your email (Click here for details on search).

If you are a user that likes to sort their email into folders, please keep the requirements below in mind when creating folders.

Summary:
- Don't use special characters, especially _ \ / | ( )

- Do not create duplicate folder names - best not in sub folders either

- Keep your full folder/path name length under 130 characters 

Acme Company - > Products - > Testing - > New

That means that the last folder actually has a title that looks like this:
Acme Company\Products\Testing\New

And is already 33 characters long!

Click here to go to the full article on the IBM website

Rules for creating folder names
In addition to the folders that are standard in the mail file, you can create your own folders that display in the mail navigation pane. When creating a folder, you should be aware of the limitations for folder names. The limitations apply whether you are using the Notes client or the web client.

Folder names can be any combination of characters, including letters, numbers, spaces, and punctuation. However, a few characters serve a special purpose. Results are unpredictable if these characters are used.
Underscore (_)
Backslash (\)
Vertical bar (|)
Control characters (codes less than Unicode 32 decimal) cannot be used. For example, do not use tab as a character in a folder name.
Parentheses can be used in some parts of the name. You can use a single parenthesis, such as animal (names, or enclose a portion of the name in parentheses, such as animal (names). However do not enclose the entire name in parentheses, such as (animal names).
Case is preserved in folder names, but they are not case-sensitive. For example, Notes does not distinguish between a folder named Animal Names and one named animal names. Duplicate folder names are not allowed unless they are in separate subfolders. So if a subfolder named Animal Names (mixed case) already exists in a folder, you cannot create a folder named animal names (all lowercase) within the same folder.
The full folder name, including all aliases, can have up to 64 bytes. English characters each use one byte, but in other languages, characters often use more bytes per character. Subfolder names have a 130-byte limitation, which includes the backslash (\) character. The subfolder customers\issues\resolved for example, has 25 characters (25 bytes in English).

The total number of views and folders that can display in the navigation pane of the Mail application varies depending on the fonts used to display their names, as well as other factors in the design of the pane. Also note that some folder names are reserved for Notes application design, such as Inbox, Calendar, or Trash. These names should not be used.