It sounds as if you are doing everything correctly. Is the recipient using settings that switch it off? Perhaps it is the case that the server your recipient uses does not allow return receipts. General info: http://kb.mozillazine.org/Figuring_out_whether_the_recipient_read_your_message How to select return receipts: On a per email basis: click on 'Write' to create a new email. Write email then click on 'Options' in the top Menu bar select 'Return Receipts' and or Delivery Status Notification' click on 'Send' To set up an auto always request a return receipt and determine how Thunderbird handles return receipts: * Via 'Menu bar' toolbar: Tools > Options > Advanced > General Tab or * 3bar menu icon > Options > Options > Advanced > General Tab * click on 'Return Receipts' button * choose settings. * click on OK * click on OK to save changes Options.

Thanks. At least I'm doing the correct think. It's not me, it's the others.