Not receiving email from sendmail with domain set locally in hosts file
I have my craft cms set up to send emails from the cms using sendmail.
The domain is currently pointing to another server while we re-build the site on inmotion.
I have set the local hosts file to use the domain locally so I can test the site whilst in build.
I have tested the forms on the website to see if emails are recieved from the cms scripts.
There are 2 emails being sent. One to several admin email addresses and one to the sender as confirmation.
When tested I receive the email confirmation and I also receive my admin email. But the other 2 admin email addresses that are using the domain that will be transferred are not.
The send email is set up to send from the domain name that will be used once transferred.
Why do I get the emails and the actual domain admins do not?
Is this something to do with inmotion or is it to do with the recieving domain email?
Any advice welcome.