Currently, when users are invited to join a Smartsheet account they receive a standard, system-generated email with no custom message. This has resulted in some users contacting the sender or a Smartsheet administrator, if they know one, to ask whether the email is legitimate or a form of phishing malware.
The system administrator / sender should have the ability to add a customized note to the invitation to explain the invitation's purpose and legitimacy.
To add to @Pat Canning's request, it would be nice if we could set the From: address in the invitation email to be a sysadmin other than the main contact sysadmin. E.g., you might have a licensing admin that's different from the main account/billing admin.