SMTP connections with 3DES encryption

I would like to understand some information about Gmail.

I was reading on Google's blog that Gmail will no longer accept SMTP connections with 3DES encryption.

In other words: As of May 30, email systems that use this algorithm will no longer be able to deliver messages to Gmail accounts. As an alternative, Google recommends that servers be configured to use TLS.

I would like to know what encryption is used in emails and, if we use SMTP with 3DES, if we can change it to TLS.

Link: https://workspaceupdates.googleblog.com/2025/05/update-for-gmail-support-for-the-3des-encryption-cipher-for-incoming-smtp-connections.html