The Stop action will remove the replication entry from your list and nothing more in your case. At this point no deltas is transferred from site to site B. Since the mail server has run for some time there is difference between what you have on site B and on site A.
What you can do is to configure a replication from Site B to site using the source VM on site A as a initial seeds (http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.replication_admin.doc%2FGUID-C7CD1006-7E2F-42B3-A3EC-429F365140E1.html
Once you do that you will sink sync data to site A and code do recovery on Site A and start using it from there.
hope this helps