Unsilent errors reading mbox files

Changelog.md

@@ -11,6 +11,7 @@ Changelog [format](http://keepachangelog.com/en/1.0.0/)
 
 ### Changed
 * GODT-511 User agent format changed.
+* Unsilent errors reading mbox files.
 
 ### Removed
 * GODT-519 Unused AUTH scope parsing methods.

internal/transfer/provider_mbox_source.go

@@ -99,7 +99,10 @@ func (p *MBOXProvider) updateCount(rule *Rule, progress *Progress, filePath stri
 	count := 0
 	for {
 		_, err := mboxReader.NextMessage()
-		if err != nil {
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			progress.fatal(err)
 			break
 		}
 		count++