Has anybody received this
You are receiving this message because our reporting indicates that your organization is still using one of those unsupported TLS versions to connect to Exchange Online. Mailboxes are still connecting using SMTP Auth client submission via smtp.office365.com with TLS1.0 or TLS1.1. You can find out which mailboxes by using the SMTP Auth Clients report described in the blog post linked to below.

Unfortunately there is no support for TLS 1.2. You will have to use a provider like gmail to be the outgoing server. I have come across this a few times.