Hello Finn from EducatedSingles !

Well, it's possible only if make all users refused to get newsletters as agreed to get those letters :-)

It's possible to do with the following MySQL queries (backup the `sys_accounts` table first):

UPDATE `sys_accounts` SET `changed` = 1 WHERE `receive_updates`=0;

UPDATE `sys_accounts` SET `receive_updates`=1 WHERE `changed` = 1;

Then make mass mailer performance.

Then it will need to back the "opportunists":

UPDATE `sys_accounts` SET `receive_updates`=0 WHERE `changed` = 1;

UPDATE `sys_accounts` SET `changed` = `added`+3600 WHERE `receive_updates`=0;