User needs to register her/his Gmail account with Offmail app. It is also necessary to allow the app to use your Gmail account to access emails. But Offmail app will NOT know, have access or store your password. At the moment app can only work with one Gmail account, but handles multiple phones and/or phone numbers.
Each email is converted to a sms (text) message and sent. Therefore the user must be able to send sms (text) messages to be able to send emails when internet is unavailable. Since sms messages cost for both user and our server, the emails sent in this way require credit which can be purchased inside the app. The price to send each sms (text message) for our server is 0.03 EURO (this does NOT include the cost of sms that user has to pay to her/his operator). Each sms is 140 characters long, therefore if the email lengh is longer than this, app divides the email to many sms messages (and therefore cost is more than a single sms with 140 in these cases).
Because of the costs, the fetching of emails in Offmail mode is restricted to emails from important contacts of the user. The user must choose the contacts (email addresses) of the important people. This list must be made during online mode because the list must be communicated to Offmail servers. User can purchase credits from Google Play inside the app for Offmail sending. Each credit is equal to 1 EURO.
When sending email in Offmail mode, each email is sent individually (but is divided to many sms if necessary based on its length). In fetching in Offmail mode, user first needs to request a fetch via a single sms (text) message to Offmail server. Offmail server then sends the UNREAD emails to the user (also by sms). This may take a few minutes. User receives an encrypted sms message that contains user's new inbox UNREAD emails, or a sms that tells the app there were no new emails to fetch. Your phone must be open to receive sms messages from Offmail server (for example number must not be in DO NOT CONTACT LIST in India).
Or direct message to twitter @offmailapp
2. Kievstar, Ukraine
3. O2, UK
5. Hungary, Vodafone
7. Indonesia, TELKOMSEL
8. Germany, Operator: Aldi-Talk (Medion Mobile )
9. Japan (Softbank)
10. Russia Megafone tested
11. Serbia Telenor
12. Vietnam Viettel
13. Australia OPTUS
14. Latvia LMT
15. Lithuania BITE
16. Finland Sonera, TeleFinland
17. Kenya Safaricom
China Mobile does not support fetching by Offmail but sending works.
UNICOM supports send and fetch by Offmail
The price list for Offmail sending and fecthing: