Some organizations use Internet mail for communicating with external recipients and another mail transport for communicating with internal recipients. This results in external recipients having one type of e-mail address and local users having another type of e-mail address. This is both confusing and inconsistent for the user.
WorkgroupMail can enable your users to send e-mail to each other locally by using the standard Internet addresses associated with each user. If the loopback option is set, WorkgroupMail will detect any outgoing messages that are intended for local recipients and will not send them out to the Internet. Instead the messages will be looped back as incoming messages ready for the local recipients to receive.
You can instruct WorkgroupMail to loop back messages intended for local recipients by selecting the Loopback page of the Local Options property sheet.
Check the Loop back radio button and press OK.