Not sure if this is where I should put this so if this isn't right please just move it elsewhere.
A local construction company hired me to create a website for them and provide 3 mails for their 3 employees including the 2 engineers. So I created index page for now saying their site is underconstruction since they aren't sure yet what to put there. but its certain they want email addresses.

I just avail a shared hosting for them and then created the 3 emails which are
Now, I'm not sure how they can exactly access their emails without getting into the cpanel which link should I provide for them to access messages to their emails?