Log into your WHM control panel and search restart services option. Under this section, you will find many services available on the machine like DNS, FTP, HTTPS, IMAP, POP3 etc. Now select the one you want.
To access WHM you have to enter the correct WHM username in the given “Username” text box. Again enter the corresponding password for the WHM account in the “Password” text box provided. Now click on “Log in” button.