Hi @Daniel_Sun, yes, you can have an email address at your custom domain, but you have to set that up outside of Webflow.
For example, if you registered a domain with GoDaddy, they may provide email services at that domain. If you point your A record and CNAME record to Webflow, that only impacts the site hosting side of things, and keeps your email settings with your domain registrar.
One common approach is to use a dedicated email provider (e.g. Google Apps), in which case you’d point your MX records to Google’s servers, and your A records to Webflow’s servers.
At some point in the future, we want to make it much easier to register domains, set up email service, etc through Webflow, but that’s probably a ways off. Today, it’s a bit more of a manual process.