We have been using Your Mailinglist Provider for several years for some of our websites. The service has become better over the years and they keep on adding new features as we speak.
You can collect subscribers in an easy way with YMLP. The software lets you build forms with a few clicks. You can choose to only ask the email address, but you can add as many text fields as you like.
Creating emails is very easy with the build in editor. However we still prefer to send out our own html emails. A great advantage is that YMLP automatically generates a plain text version of your html mails for email clients that can't read html.
Emails are sent out very quickly and you immediately get all the statistics you need. Number of opens, clicks, who has clicked on which link,... Everything you need to know.
A great advantage is the API that lets you integrate the YMLP software in your website.