2. Recipients of the emails are registered users of the system. There will be no promotional emails sent or no emails to any unregistered users.
3. As there is no promotional email sent, I think they do not need to unsubscribe. All the mails will be verifications or some events triggered by them in the website. (Transaction info etc). If they want to unsubscribe, they are to stop using the system. I can delete accounts on request.
4. No
5. No (But I will monitor any abuse)
6. No
7. Never
8. Hello [Name],
A new transaction has been made by [someone], the owe you BDT [amount]
Details: [details]
Amount: [amount]