Check spam
It is possible that emails may be directed to your spam folder.
Check for typos in Mosaic Settings
Confirm that the email address entered in the Mosaic Settings is accurate. The invitation email will be sent to the email address you provided on Mosaic, if the email address is incorrect, then you may not receive the email.
Check Organization settings
You must enable the notification email settings in the organization settings page in order to receive invitation emails after submitting the invite form.
This is OFF
This is ON
If you do not wish to turn on the notification email for the organization, after submitting the invitation form and seeing the member in the Organization Settings > Members > All Members tab, you may use the "Resend Invite" button to manually send the email.