Users of earlier versions of Outlook require a different set of instructions to forward distribution lists. For a start off, sending an email distribution list to someone in Microsoft Outlook 2000 or 2003 will only work if Word is not being used to write emails. You can check and disable this in Outlook by going to the Tools > Options box.
On the Mail Format tab, look for Use Word to edit e-mail messages (or similar, depending on version) and ensure the checkbox is cleared.
Click OK to finish; you will then be ready to include a distribution list from your Contacts into a new email message.
To do this, start a new email message (File > New) and go to the Insert > Item... menu. In the Insert Item window, select Contacts in the Look in: section, and in the Items: list, in the lower half of the box, find the distribution list you want to send.
In the upper right area of the Insert Item window, check that Attachment is selected. Select your distribution list of choice, and click OK – the list is now added to your email message, which is now ready for you to forward at your convenience!