In order to organize the way how certain people at the end of the contractor only receive particular requests/emails, or get notified about the issues concerning them, the contractor must leverage what we call 'User groups'. They can create custom user groups and add desired users to it from all the users they have on the account.
The custom user groups' concept will come in handy whenever any Managing agent client creates a new job and assigns it to a contractor. At this point, the Managing agent user will need to further select specific user group to assign the job to, so that the members of ONLY that group will get notified about the request at the end of the contractor.
Setting up user groups-
The admin user on the contractor account can setup a new custom user group, under SETUP/User groups-

They must make sure to give it an intuitive name for the group that makes it easier for a Managing agent user to get an idea about its purpose (giving an intuitive name will help when the MA user creates a request and can't decide which user group should they select to assign it to).
So for example, if you need a user group for helpdesk, please create one with name 'Helpdesk queries', this will signify that this group is meant to deal with helpdesk queries ONLY. Select 'custom' as the type of group, and give the name in the internal name, and accordingly tick required boxes.
Adding users to user groups:-
Now, we must add members to this newly created user group to make sure only certain people receive what they are supposed to receive. We can do that in below 2 ways -
- Either click on SETUP/User groups and click on SELECT ACTION for the new group and click on MEMBERS-

2. OR, click on SETUP/Users, and click on SELECT ACTION/groups and tick the new group for the users you wish to add to the new group, and click OK-
This way it can be ensured that only people in that user group are being notified for stuff falling within their jurisdiction or requiring their attention.
For more ideas on how a Managing agent user can set this up for their contractors while registering new contractors, please refer the below article-
https://dwellant.zendesk.com/hc/en-us/articles/4407739542033-Adding-Groups-to-a-Contractor
About the email notifications settings:-
If any user need to change their email alerts or notification settings, they can do so by clicking topright corner drop-down arrow (its a link with their Display name) and clicking on 'Settings & Account info', and this will bring up below window. You can choose and select which boxes to tick/untick to control the emails to your inbox.