I am able to have users login to their Outlook clients and be able to change the FROM field to a distribution group address where they have send as rights to. Some of these users do not have access to use Outlook and only use Outlook Web Access. How can I direct these users to be able to send emails appearing to come from the distribution group where they have the send as permissions granted? I have searched all over the internet and I am able to have users send from others users mailboxes in owa, but I need them to be able to do this from their distribution groups also. TIA!

THat is not a feature of OWA 2003. You'll have to get them outlook and if they are remote, just use RPC over HTTPS