I don't seem to be able to reply to people who have kindly redetermined a record or added more information
When I look at notifications it's empty although I get email notifications.
If a record has been redetermined and then accepted there probably isn't a need to reply, but if you want to see the record or add more information then you should be able to click through to it from the notification email. If not then you can go to Explore > my records and when you go down to your records there is a spanner icon in the top right. If you click on that you can choose which columns are displayed. If you tick the box for "verified on" then you can order your records by the most recent ones to be verified, which should make finding records that have recently been looked at a lot easier.