MailOptin

MailOptin is a popular plugin for creating popups; it displays signup forms, targeted messages, and call-to-actions across your website with a popup, in-post subscription form, notification bars, slide-in, sidebar widget. This plugin will automatically notify your subscribers and WordPress users whenever you publish new content on your blog and automatically sends the blog posts as an email newsletter. Popup optin forms overlay above your content to grab your visitor's attention. The plugin allows you to place a call-to-action button to grab your viewers' attention and making them act.