Feel free to use this template, which I made with the help of Dear Landlord/Tenant,
We hope you're well.
We just wanted to say how much we like the area and your street. We’d be genuinely interested in renting a property here if one becomes available.
If you’re a tenant and thinking of moving out at any point, or if you’re the landlord and the property might be coming up for rent, we’d really appreciate it if you could let us know. The same goes if you hear of anything else nearby that might be coming up.
Thanks very much for your time, and all the best.
Kind regards,