Need help fixing email hosting issues

We have migrated to G suite overnight, I want to send, receive and view my email in Outlook app though.

I have connected the g suite email to outlook, but am unable to send emails. they just stay in the outbox.

We previously had hosting with OVH I believe, but you will need to confirm that. We migrated due to outgoing email errors, our OVH IP was blacklisted.

I need assistance getting my email to function normally for the three business emails I have. What ever is required to do that.