Subdomains now available as sending domains in Reach

Users can now choose between a domain or subdomain when connecting a sending domain for the first time, or switch to a subdomain if they already have a domain connected. Using a subdomain for sending is standard practice in email marketing—it keeps marketing and transactional traffic separate from the root domain, so DNS records for other services remain untouched and reputation is isolated per use case. For internal domains pointing to Reach's nameservers, the configuration is automatic. For external domains, users must verify ownership first before switching to a subdomain.