I'm migrating a 5.5 server to E2K3. I've replicated my public folders and
my E2K3 server is now taking all inbound SMTP traffic. If I try to send
mail from an internal account to a public folder it works just fine. If I
try to send mail from an external mail account, it is refused with error
5.2.1. According to MS, this error can be caused by "an absent Master
Account Security ID number (SID) on the recipient". I'm unsure how to fix
this for my public folders.

Any help would be greatly appreciated.

-Eric