Yep, Mailgun tracks all of the typical events that occur with emails: Opens, Link Clicks, Bounces, Unsubscribes and Spam Complaints. We make that data available to you via the Control Panel or through the API. In addition, you can set up webhooks and we will post events to your URL. Take a look at our tracking documentation for more information.
Mailgun does have features to help you with list management. First of all, we will not deliver again to recipients that have hard bounced, unsubscribed, or complained of spam. This is to maintain your email reputation. You can remove emails from these do not send lists if it was a temporary issue. You can always access this information via the API or Control Panel to update your lists.
You can think of hard bounces like permanent errors and soft bounces as temporary errors. We will stop attempting delivery after one hard bounce. With soft bounces, we keep trying to deliver but eventually we will stop trying to delivery in accordance with the receiving ESP's feedback.
It's up to you. You can use Mailgun's unsubscribe handling. You can include our unsubscribe variables: %unsubscribe_url% (for the entire domain) and %tag_unsubscribe_url% (for just emails with this tag) and we will take care of the unsubscribe handling for you. Take a look at our unsubscribe documentation for more information.
It's very simple, just tag your emails with the appropriate o:tag parameter and Mailgun will group all of the events that occur to emails with that tag. Our analytics reports include those tags as one of the dimensions by which you can view and filter data. You can have multiple tags per email and up to 4,000 total tags. Take a look at our tagging documentation for more information.
Since creating a campaign is as easy as including an arbitrary tag, yes. You can easily view which campaign is performing best by viewing the data grouped by tag in the Analytics tab of the Mailgun control panel.
This has been a popular question, so we wrote a blog post about it. Basically, the Message-ID in the original email is included in the In-Reply-To header in the reply email. So you can use that to track which specific email was replied to. Mailgun will automatically include a unique Message-ID or you can set your own.