Because IMAP and POP3 are different, but they use the same id.
So I think we have two solutions:
1) Rename the locators. IMAP and POP3 use their own methods. If Gaia have any change, it will be more flexible.
2) Rename the locators and methods. IMAP/POP3 all use the same methods.
Now we use 1) as solution, if you have any idea, I am okay for other solution :)