is there any way to find Workflows which contains notifications to a specific email address?
Any way to get this with SQL-queries against Nintex database?
it's not in the NW database, since the workflow definitions are stored in SharePoint. So potentially, you could query the SP Content Databases, but I'm afraid I don't know where the specific data you need is stored.
What I've done in the past, is run a PowerShell script on the server you installed NW on. It'd go through all the workflows in your farm, and look for ones with a specific action. You'd need to tweak this to look for your email address that you're after.
Nintex Workflow - PowerShell Find Workflows that contain a Specific Action Part 4 - Vadim Tabakman
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