Michael,
Yes, you will need to reprocess your original document. It sounds like after you map to X12, you immediately invoke wm.EDIINT:send. A better approach is to submit the X12 data to Trading Networks, and then create a processing rule that will deliver your X12 data to another Flow service that will invoke wm.EDIINT:send. This approach allows you to reprocess the X12 document within TN if the EDIINT message needs to be resent. It will also give you more flexibility down the road if some partners do not want to receive via AS2. They may want to communicate via FTP. If you always invoke wm.EDIINT:send after mapping to X12, you will not have this flexibility.
Also, by submitting your X12 data to TN, you can perform FA Reconciliation if you want to.
HTH
#Integration-Server-and-ESB#webMethods#edi