I have to send large number of emails every month. Is there a service I can use to help me do that?
I am not concerned about the cost. The only thing I am concerned about is that the emails should not have "watermarks" (or banners from the service I am using). I tried MailChimp and several other mass email services but they all seem to include their banners indicating that the emails were sent using some email service.
In other words, every email should look like it is sent from a human user.
I am a PHP developer myself and my first approach was developing a mass emailer myself, but according to the first answer on this question it seems very very hard to do it yourself.
So, is there an already existing mass emailing service that would let me do that kind of thing?