I dont think i understand what you mean with localhost record. But i dont think this Record has something to do with your Mail Problem either. Your Domains MX Record correctly shows mail.peak-careers.com
and this resolves to the Correct IP. How do you check for new Emails?
Kindly, may I ask have you checked the suggestions from the below article?:
Moreover, if you created an A mail record with the content value of your IPv4 hosting provider and made it cloud (DNS only), then in your e-mail client, like MS Outlook, Mozilla Thunderbird, etc. you should use mail.peak-careers.com as incommming/outgoing server.
Also, an MX peak-careers.com should have the content value of mail.peak-careers.com.
Are you sure your e-mail server is actually working and listening on needed ports for SSL connection (110, 143 and 25 yes)?