Some times you may wanted to add mail enabled public folder as the member of Distrubution list and you wanted to send copy of mail to PF which is sent to distrubution list.  For this you may need to add mail enabled public folder as the member of the DL

Its not possible add public folder as members of DL in Exchange 2003. This can be only done from Exchagne 2007.
Throught Exchange 2007 you can add both throught Exchange management console and Powershell command

Powershell command
Add-DistributionGroupMember  -Identity “DLName”  -Member “Email address”

Exchange Management console
Expand Recipient Configuration -> Distibution Group -> find the requied DL -> Add the same