Groups dropdown exceeded
There are more Groups on the account than can be shown in the Sender dropdown (approx. 10).
Troubleshooting steps
Use a partial name search to find the Group:
User profile is not a member of Group
Your Administrator log-in profile must already be a member of a Group to add it to a Sender via Senders.
Troubleshooting steps
Add your user log-in profile to the Group, or add the Sender to the Group from the Group page (see Create and manage Groups).