When CodexFit sends email, it sends email like it's coming from the email address you have setup on your organisation(s). I.e. if you set the name as CodexFit and the email as firstname.lastname@example.org, when the email arrives in the customer's inbox, it will show as coming from the email address email@example.com with the sender name CodexFit.
If CodexFit sends an email to a customer and it bounces back (i.e. the email address isn't valid or the inbox isn't receiving mail), the email will automatically be blacklisted from receiving further emails.
If CodexFit sends an email to a customer and the customer or their email server submits a complain, CodexFit will also stop sending emails to that email address.
If either of these happen, and you'd like the email address unblocked, please email firstname.lastname@example.org.
The emails are blocked from further sending to protect your domain from getting a bad reputation.