email fetcher minor modification

cmsWebApp/src/performa/utils/PerformaEmailFetcher.java

@@ -315,7 +315,7 @@ public class PerformaEmailFetcher implements Runnable, InitialisationParticipant
                     @Override
                     public void run(ObjectTransaction objTran) throws FieldException, StorageException
                     {
-                        if (jobIdentifier != null && !jobIdentifier.isEmpty())
+                        if (jobIdentifier != null && !jobIdentifier.isEmpty() && StringUtils.isNumber(jobIdentifier))
                         {
                             Job     job =   Job.getJobByID(objTran, Long.parseLong(jobIdentifier));