SMS as reminder, after survey link has not been opened for e.g. 4 hours

Question

Dear Support Team,

In my study I will have various groups of participants who will receive the questionnaires to different (pre-defined times). Now I would like to send them an SMS reminder if they have not opened the link within e.g. 4 hours after receiving it. These reminder messages will need to go to various phone numbers across the world. Is there any option to do this automatized within SosciSurvey? (I only found an answer for randomized SMS sendings).

Best regards, thank you,
Julia

(The study is programmed in english, however I can also understand a German answer)

Answer 1

The trick is to always prepare the SMS via mailSchedule().

And then, if the link was clicked, place a mailRevoke() in the second questionnaire to cancel the SMS. If it is not cancelled within 4 hours, it is sent :)