Using one manager's email address across several creators
Summary
Every contact email address in your GRIN account has to be unique, so the same manager or agent address cannot be saved on more than one creator profile. To keep several creators under one manager and still be able to reach them, assign the manager as the primary contact and give each creator a distinct alias of the manager's mailbox.
Why this happens
An email address can exist only once in a GRIN account, whether it sits on a creator, on a manager or agent, or on a user of your account. If you try to reuse the manager's address on a second creator, GRIN tells you the email already exists.
Leaving those creators without an email address is not a workaround. A creator without a valid email address is skipped when GRIN builds an email sequence, and GRIN has no address to send them anything, including the verification link for their Live Site. Creators with an empty email field will hold you up later.
What to do
Create the manager or agent once. In Contacts, open Creators or Prospects, then Settings, then Managers / Agents, and select Create. Save the manager with their real email address.
Assign that manager to every creator they represent, then switch the Primary Contact on each creator profile to the manager. From that point on, email to those creators goes to the manager, both sides of the conversation appear in Messages, Inbox, and replies go to the primary contact.
Give each creator a distinct alias of the manager's mailbox. In the creator's Contact Information, use a variation of the manager's address, for example manager+creator1@agency.com on the first creator and manager+creator2@agency.com on the second. Most providers, including Gmail and Google Workspace, deliver anything after the plus sign to the same inbox, so the manager keeps receiving everything in one place while each creator now has a unique address. That is what makes them eligible for sequences, creator alerts and Live Site verification.
Good to know
If your provider does not support plus addressing, or the agency would rather not use it, use a different real mailbox for each agent at that agency instead.
Use aliases for the contact email only. For creator payments, enter the payout email exactly as the payment provider expects it.
Deleting a manager record to free up an address is not recommended. Deletion is permanent and it removes the manager relationship from every creator linked to that record.
One address per account is a platform rule, not a setting, so it applies the same way to creators, prospects and applicants.