Config 2 account

Hi all ,

i ve an Exchange 2013 Cu3 config . Client have Outlook 2013 config with Exchange . I want config another account  Pop with repository Exchange based. If i select this method i can send email normally , if i add an attachmennt Outlook give me error 0x800ccc13 . if i select a new file pst for this account have no problem ! 

Is it auth problem or what ?

Thanks a lot

   Andrea

Wish Best Christmas Holiday