Depends. Usually not. It hops from your computer to your email provider which then looks up the server of the recipient and sends it there. The recipient's server might send it on internally and in big installations probably does so.

It is theoretically possible that one of the involved parties has a third party authorised to accept mails on their behalf in case of outages. I don't believe that is very common nowadays. It's much more likely that your provider will keep the mail for a few hours to days when it can't reach the recipient.

But ideally only your provider and the recipient's provider can read the mail with all connections in between being encrypted. There's just no guarantee that all paths are encrypted. But I think nowadays that is much more likely than it used to be, thanks to Let's Encrypt.

Now, if you don't want any of the servers to be able to read the mail you have to encrypt it with something like GPG. But for that to work you need the recipient's key. But hardly anyone uses that. And it only encrypts the content of the mail. Not the metadata.

If you control the DNS and the mail server, you get to decide where it goes. However, if any senders or recipients are on gmail, Google basically has all of those emails' content.

That was the theory, nowadays moest email goes from google or microsoft to google or microsoft. At least 99% of the rest goes directly from the senders provider to the recipients provider. Afaik none of the larger providers still accept non-TLS connections.