You are downloading the Mailling Stuff XAP file v220.127.116.11 for Windows Phone. Mailling Stuff is a free and useful Business app: This is a handy app, which provides you with the direct online navigation to the Outlook.com, Gmail.com, Yahoomail.com and Rediffmail.com. Can read ... You can now download the offline XAP file to install & try it.
Download Locations for Mailling Stuff 18.104.22.168 XAP file
Important Notice: Now Due To Unspecified Limitations, You Can Not Use The Offline XAP File To Install It Any More.
To try to install it manually from an SD card, you should choose one of the server location above to get the offline Mailling Stuff XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.