Translation (MAPI) error 0x80070057

Your question covers a lot of territory. What format are you importing from?

If it's from a PST file - no need to import. Better approach is to open the PST file that contains your contacts and copy them to the desired destination folder. Not withstanding that, if importing PST2PST - if the source PST file has an underlying error (or errors) - this could easily occur. Any import/export process cycles through the file on an item by item basis which could easily encounter things that you would not see in normal day to day activity if the item is question is never referenced.

If it's from a txt or xls file - you have a data related issue either in the field (column) names or the data itself. If it's a field name related issue (header row having the problem) - no contacts at all would be imported. If it's something related to the data itself - contacts would be imported up to the point that the invalid record was encountered (unless of course it coincidently also happened to be the first data record). If one or more items have been imported - check your file to find the last item that was imported - the one that follows is the one which has the problem.

In short - the error indicates a data related issue of some kind whatever the source but unfortunately the Outlook import/export wizard is not the most informative when it comes to explanations.