You have emailed an invoice and then received the following email:

 You may receive this message for one of the following reasons:

• Establishments have been created in your organization and you belong to a group containing several of them (user with a multi-establishment profile).
• Another company has authorized you to issue invoices on its behalf (user with a multi-company profile).

In neither case can SY identify which establishment or company is issuing the invoice simply from your email address.