GMail

I use Gmail for the following reasons:

1. It provides a lot of space – currently 7523 MB. I’m currently using 17% (1337 mb) – so I don’t have to delete any mail.
2. It provides themes which makes it attractive.
3. The POP3/IMAP settings are much easier which directly pulls all the mail to my phone's mailbox
4. With the priority inbox, I can be able to read the important ones alone and read others when I'm free.
5. I can filter my mail.