Disabling Outgoing Mail is not applied when Jira email batching is enabled

Summary

• As a Jira administrator I disabled the outgoing mail feature on my cloud site, however, I'm still receiving notifications.

• These notifications are specifically received from next-gen projects.
• The change to outgoing mail feature is not getting applied to next-gen projects.

Steps to Reproduce

1. Go to cloud_site/secure/admin/OutgoingMailServers.jspa
2. Disable the feature.
3. Go to a next gen project, try to trigger a notification by creating a new Jira issue and assigning it to a user.

Expected Results

No email notification is sent.

Actual Results

An email notification is sent.

Notes

This can be considered as related to report JSWCLOUD-17157.

Workaround

Currently, there is no valid workaround yet.