The Mailpoet Newletters plugin is one of the best things you could have added to your wordpress website. With the Mailpoet Newletters plugin you pretty much have a beastly newletter sender inside you worpdress dashboard that you can access whenever you're on the back end of your blog or website. There's not more logging into a third party service to send out your newsletters or logging into a different hosting account or server to send out a blast. You can configure everything within you dashboard which is very convenient since you're most likely on there posting new content regularly, or at least you should be ;)
With the Mailpoets Newsletters wordpress plugin you can create newsletters, automated emails, post notifications and autoresponders with ease. Everything will send out flawlessly through your gmail, own servers smtp or a third party smtp server like SendGrid or Amazon SES Mandrill.
The real beauty of this is that you have a drag and drop editor so you don't really need any coding or programming knowledge to get a well made HTML elegant looking email to send to your subscribers. There are over 70 different themes included within the Mailpoet Newsletters plugin and there are also photoshop files in case you want to get some more customization done.
Mailpoet Newsletters also has some premium features if you want to upgrade, but they aren't necessary to send out newsletters. These add ons will definitely help your lists, but you aren't forced to upgrade if you don't want to. If you have over 2,000 subscirbers then you'll need to upgrade. The basic account only allows 2,000 or less subscribers to be mailed out to, but a lot of people may not need to upgrade. Another great feature, that's worth the premium price if it were a stand alone feature, is the bounce handling which helps keep your list clean. If an email gets bounced back, that email is removed in order to protect your list from automated spam detectors which could potentially harm your list even if it's legitimate
If you want to get an email sender in your wordpress dashboard, I suggest you check out the Mailpoets Newsletters and test it out a bit. It's free to use unless you have over 2,000 subscribers, but you can easily test it for free before you upload your lists