On the Communication Center page of Sell, I see this message: Your emails are still synchronizing, or there are no results matching your filters. What does it mean?
This message indicates that there is an issue with your email provider. The email integration in Sell requires that you enable both IMAP and SMTP protocols on your email server for both sent and received emails.
Consult the email administrator of your email provider to fix this. For more information, see this article: Email troubleshooting: SMTP and IMAP Settings.