Hi Antbrew !
Solo doesn't currently show an overview of reminders or emails sent from the app, but we like that idea!
We do already have a similar idea here: Read receipts for emailed invoices | MYOB Community
I highly recommend adding your vote and feedback there, as this will help us prioritise what is important to our Solmates.
That said! We would really like to check under the hood to see if we can figure out why you did not receive a copy of the reminder. Would you be able to jump into Solo, tap More, then Chat to us. You'll get a chat bot at first, but you can ask to speak to an agent, from there you can select to "Raise a case with our Solo support team" and we will take it from there.