Email Reminders to Users

There are Subscriptions and "Reminders" which can be sent out Automatically.

Here is some help on Subscriptions.

https://help.quickbase.com/user-assistance/about_subscriptions.html

If you can create a report filers by where the current user is the one who needs to be reminded, then you can create a single report and set it up to go on a Subscription to all users.  Then only users with records on their report will receive an email

Is the issue that users are forgetting to fill these things out when submitting the record and need to be reminded to go back when the error is noticed? Or are they following a process that requires them to go back days later and update a record?

Depending on the answer to that there are a few things you could do.

I often build "missing fields" formulas which do not prevent a user from saving a record; but do visually remind them that things are missing.  This is especially prevalent when a Form is divided into TABS.  If you force users to put data in by making fields required in a Form, you are probably opening the door to "bad data" entry or preventing users from different roles from editing records.

The advantage with a formula like this is that you can list all the fields that need to be populated; and as they are the message adjusts.  You can also use this on reports - a good way to setup subscriptions to "Record Owners" or "Last Modified By" users when the missing-fields message is populated (or a longer version would be a report with filters that look for empty values across ANY of the required fields).

Harassing people by email generally leads to a "notify@quickbase.com" ignore behavior, so something onscreen to remind users while they are in the record to finish it before saving is usually more productive.

For attachments, build a checkbox that looks for the file attachment field to be populated; then look for that checkbox value to evaluate if it is still missing.