Could you please refer below sample
https://github.com/OfficeDev/microsoft-teams-apps-newemployeeonboarding/tree/79cdcfa8fdfe80ae0546ef1825808ff52c5e4112
In this sample in SendWeeklyNotificationAsync() function the notifications are send using list.
You can use this function for how to access list and write your custom logic to send email.
Thanks,
Nivedipa
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