Gmail. Rapidly becoming the most popular mailing service, Gmail comes feature-packed and easily surpasses other mail services in terms of features, user-friendliness and storage space. Featuring a adept AJAX engine, the interface of Gmail is very responsive and in a while, you forget that you are on a web page. It feels like you are using a mail client. Also, the conversation feature is very handy and keeps your recent mails list compact and yet gives you easy access to related mails.
With all these awesomeness, I still dont use Gmail. Do you know why? Because it is spooky. I would request everyone one to scoot on over to https://google-watch.org/gmail.html and read the article there. Gmails privacy policy itself is scary. Also, Gmail never deletes any of your mails. It takes a major effort to delete mails and even then, they have accepted that a copy is still maintained on their servers. Also, they associate keywords with email addresses. As in, prolly, the words most frequently appearing in your mails would be associated with you. So, now how many of us would like people who have access to gmail servers look us up and say hey! this person is into this, this and this .. I wouldnt.
With all its advantages, Gmail still doesnt come across as a trustable service. Personally, I prefer to stay far away from Gmail.