The reason for this is simply authentication and security and is an industry convention with email marketing systems (E.g with others systems it might say "From Me at My Company via 23764.mailsender.com", this is just the style that we use).
1) It prevents your domain from being blacklisted if an email sent causes lots of complaints (it will be our yourcrm.co.uk that gets blacklisted instead, so we don't tolerate any sending of spam from InTouch).
2) It helps with deliverability. As we have an excellent reputation and delivery success of over 95% (above industry standard), it helps your email to arrive at it's destination in the recipients inbox, because we are authenticated and trusted by the ISPs.
However if you wish to use your own domain to authenticate emails we can do this too, please see more information here.