Ok Sorry Jan.
Here it is:
1.I made a gravity forms Form where users apply to jobs and made it the default “apply-method”.
2. In the form I put a field called “category” or “region” where user set their preferences (that will be used as Newsletter Preferences).
3. I set in the Mailchimp Account (website mailchimp.com) 10-12 different lists based on every category.
4. I installed the gravity forms mailchimp addon and made it collect data from the “application form” set before.
4a. I created a new “Mailchimp Feed” for every category and set an opt-in condition that every list must match specific category.
5. Back to Mailchimp Website I created RSS Driven Campaigns based on category based RSS Url (you can find exact rss category url for WP JOB Manager in another discussion).
If you don’t need category based campaigns it will be much easier.