Outfound sends from a subdomain of your domain rather than the main domain itself. The default subdomain is send; for yourcompany.com the sending address becomes send.yourcompany.com.
Why:
- Your company's existing email (Google Workspace, Microsoft 365 and so on) keeps working as it is; your MX and other records do not change.
- The reputation of cold email is kept apart from your main domain.
- The records needed for reply tracking do not clash with your current setup.
You can change the subdomain with Change during setup. The "mail", "www" and "reply" subdomains can't be used: "mail" clashes with the email configuration of most hosting companies, "www" with your website.
Each main domain can have one sending subdomain. If you add the same main domain again, the screen says it is already added.
In a two-NS-record setup you delegate the sending subdomain to Outfound; your main domain's records and your email are not affected.