Email sending using a subdomain

Currently, we cannot have the root domain configured as the domain for page hosting + click tracking, and a subdomain (eg, mail.yourdomain.com) as the sender domain (linked to DMARC and SPF DNS records).

This goes against the email best practices of having a subdomain dedicated to email reputation.

This is also annoying because the current situation means either we have everything under the root domain, or we should use the root domain as the email sender and a subdomain for page hosting, but this is bad for branding (and simplicity).

Could you allow a subdomain as an email sender?