Notifications for deciders (search issues for pending decisions via JQL)
Each time, an issue is displayed on screen by any user, all current deciders are determined and updated within issue.property[approvals].deciders. This field can be used within a JQL statement as show on the screen shot on the right.
I try to reduce the number of email notifications to the minimum, based on my experience of the last 15 years in many customer projects: instead, I recommend to use Jira's filter subscriptions to get frequent overview emails containing a list of all issues, which have to be approved. This is much more effective then continuous breaks by disturbing, poping up emails!
If you are not familiar with Jira's feature of filter subscriptions, please have a look into the Atlassian documentation at https://confluence.atlassian.com/jira064/receiving-search-results-via-email-720416706.html
Using a JQL as displayed on the right, a decider will get a list of all issues, she/he participates on at least one approval. May be, that's too much, but you can also combine that JQL with other JQL functions to reduce the result set to your needs.
Easily, you can search for all issues, which have to be decided by the logged-in user and being in status e.g. "onhold" via a JQL like:
The indexed data are a list of all deciders including their decisions within a single string like: "admin (multi users) | fpolscheit (multi users)" having no vote or "fpolscheit(Manager)=Y:2018-09-16 13:57 | someOneElse (Manager)". The name in brackets after the user name is the name of the referred field within the related conditional/dynamic rule and set automatically. The equal sign is followed by the voting: "Y" for yes or "N" for no as well as a timestamp after a separator colon. So, you can also search for e.g. all issues, which have been vote dated on "2018-09-16", too.
More privacy and GDPR
According to the necessities of GDPR, the user's account Id will be written into the property instead of the human readable username, now! Therefore, the JQL statement has to be adjusted accordingly. Instead of the prior username you have to enter the related account id or use the JQL function "currentUser()".
The simplest way to find out the account id for a user is to navigate to the People page inside of your Jira cloud instance which you can view by navigating to the URL of https://yourJiraCloudBaseURL/people/search. On this page you can search for the name of the user that you need to find the accountID for: you will find the account ID in your browser's URL after /people/ like within the sample below.