When performing an export with Search Exporter and the Attachment is missing from the email you're trying to export, it will fail with the below error and not export the message contents:
2017-02-10 15:20:58,387 [4] DEBUG Dell.AM.Public.SDK.RestApi - Execute GET messages/{id}/raw id=20614302
2017-02-10 15:20:58,445 [4] DEBUG Dell.AM.Public.SDK.RestApi - Response is 404 (NotFound) Content-Type=application/json; charset=utf-8 Content-Length=150
2017-02-10 15:20:58,475 [4] WARN MailExporter.Exporter - Could not store message:
System.Net.HttpListenerException (0x80004005): Unexpected HTTP status code NotFound: Not Found
at Dell.AM.Public.SDK.v1.Rest.RestApi.Execute[T](IRestRequest request, RestHeaderCollection& headers)
at Dell.AM.Public.SDK.v1.Rest.RestApi.Execute[T](Object data, Method method, String resource, RestHeaderCollection& headers, String[] args)
at Dell.AM.Public.SDK.v1.Rest.RestApi.Execute[T](Object data, Method method, String resource, String[] args)
at Dell.AM.Public.SDK.v1.Objects.SDKMessage.Create(IRestApi instance, Int32 id, Int32 instanceId, String impersonate)
at Dell.AM.Public.SDK.v1.Objects.SDKMessageSummary.get_Email()
at Dell.AM.Tools.SearchExporterUtil.Exporter.StoreMessage(ISDKMessageSummary messageSummary)
at Dell.AM.Tools.SearchExporterUtil.Exporter.StoreMessages(ISDKSearchResultPage`2 searchResultPage)
2017-02-10 15:20:58,499 [4] ERROR MailExporter.Exporter - {{26edff7d-18e2-4c15-a7a9-9639a3d72010}} Could not perform export.