Changing GoDaddy DNS from Microsoft 365 to iCloud+ Custom domain email - success, but can't send emails. Do I need to remove old CNAMEs?

I use GoDaddy for my domain, and was previously using their Microsoft 365 to manage my email.

I added my custom domain to my iCloud+ account, and successfully entered the new DNS records.

iCloud says everything is connected correctly, and I am able to successfully receive emails. However when I try to send an email with Apple Mail from my custom domain, the email does not successfully send.

I thought maybe this has to do with other CNAME records that could be causing a conflict. But none of the Apple Support documentation stated anything about removing them, so I didn't.

Here's what is still listed in my DNS records. Should I delete these? Or is there something else I should attempt to resolve my issue?

CNAME DNS Records still in my domain:

• CNAME - autodiscover - autodiscover.outlook.com
• CNAME - email - email.secureserver.net
• CNAME - lyncdiscover - webdir.online.lync.com
• CNAME - sip - sipdir.online.lync.com