I am able to get main folder through console application code but not able to read sub-folders.
i have got the answer instead of going through coding..we can do it through OOTB. go to library settings to which you want to save the attachments from mail and go to incoming email settings and get mail details from SMTP server configuration details from CA and give here and then select necessary settings save it.if you get emails with attachments [the mail you mentioned at settings]directly it will save to your library. yes it's done!!!!