Invitations were sent out (multiple times, from the looks of it) to two of the people and didn't bounce — that's all we can tell you on those. They'd have to check their spam folders or ask their email server admin.
For a third person (beginning with 'n') the email bounced as an unknown user.
Any suggestions as to how to fix this?
For a third person (beginning with 'n') the email bounced as an unknown user.