You can setup your IMAP on MAC by those steps :
Step 1 : Open Application Mail on your MAC (MAC --> Mail --> Preferences ...)
Step 2 : Choose Add Account
Step 3 : Choose Other Mail Account.
Type your Email detail in the list, then click Sign In.
Step 4 : Fullfill information about your Account. Next, click Sign In.
Step 5 : Choose Mail as your Selection and click Done.
Done !