Can you suggest some best Email Marketing Service providers?
It would depend upon your goal. If it is somethng generic, quick and cheap, then you can go with Constant Contact. If you are looking for something inexpensive and branded to your company, then Loyal Customer Club is a solid Choice.
I have used quite a few. But it really depends on what you are looking for. One of the places that offers an assortment of services is vadbox.com, I found them on a forum, and have no complaints with the results.
I think you should avoid it, email marketing without email list is suspicious,they could be false claim and only using robot to hit your site so that it look get traffic, my suggestion start build your own email list from your blog subscriber and use icontact as your email tools
I use the Express E-Mail Marketing Service from XnYnZ.com and no matter where I am I can reach my clients.They provided me a list of subscribers ,and helped me to send e-mails to them,track down the result and get the valuable feedback from my customers.I was able to campaign in social networks which comes free with the plan.