Total Recipients
This one's pretty self-explanatory. It's the number of recipients on the list you sent the campaign to.
Successful Deliveries
Some emails bounce back, or get blocked by email firewalls and spam filters. The "successful deliveries" is a quick number showing you how many of your emails actually got through to your recipients' servers and did not bounce back.
Times forwarded
MailChimp lets you insert a link into your email campaign that allows your recipient to forward a copy of your campaign to a friend. This number only reflects the number of people who used the forward to a friend tool, not those who forwarded from their inbox.
Forwarded opens
Maybe your recipients forwarded your campaign to 1,000 friends. This stat will tell you how many times those friends opened your campaign. It's a nice measure of how "viral" your campaign is.
Recipients Who Opened
This tells you how many individuals opened your campaign. So if two (very sad, very lonely) people opened your campaigns 500 times each, that would be 1,000 total opens. This stat would show, "2 recipients opened" which is a lot more useful to email marketers.
Total times email was opened
This is a stat with lots of "wow" factor, but don't let it go to your head. Your email might have been opened 10,000 times, and that sounds really cool. But what if it was just one guy (a guy with way too much time on his hands) who opened your email 10,000 times? That's pretty extreme, but you get the gist. It's not a totally useless stat. For example, if you sell banner advertisements in your email campaigns, then an open is an impression, and you want to show total impressions (even if one of your recipients is a whacko).
Last Open Date
The last open date shows the last time a recipient viewed your campaign.
Recipients who clicked
This number tells you how many people clicked on some link in your campaign. Let's say you sent your campaign to 5 people. 4 of them click a link in your campaign once. But one of the recipients is our weirdo from the examples above, and he clicks your link 500 times. This "recipients who clicked" stat will show you that "5 people clicked something." Your "Total clicks" stat, on the other hand, will show "504 total clicks."
Clicks per unique open
The clicks/unique open stat tells me that of those who actually opened, 20% clicked.
Total clicks
This is the total number of clicks your email got. It's handy in determining how much overall web traffic you'll get to your website after a campaign is sent. For instance, it might be nice to know that "after every email marketing campaign I send, our website gets about 600,000 visits."
Last Click Date
The last click date shows the last time a recipient clicked on a link in your campaign.
Complaints
You know when you get a piece of junk email, you click that button in your email program that says, "This is junk" or "Report Spam"? Every time you do that, a report and copy of that email is sent to your ISP. Your ISP then sends a little warning to the sender that says, "too many more complaints, and we'll block all future emails from you." Well, whenever you send an email campaign from MailChimp, we track how many complaints your recipients submitted (we're subscribed to ISP feedback loops). By the way, we automatically remove anybody who complains about you from your list. If you don't clean your lists this way, ISPs get really angry.
It's normal for about 0.04% of your list to report your campaign as spam (yes, even if they know you, and even if they gave you permission to email them!). If you get anything above 0.1%, major ISPs like AOL will start blocking future emails from you.
Total Unsubs
If any email campaign stat is capable of bringing a tear to your eye, this is the one. We've seen average unsubscribe rates of less than half of one percent. Anything above that means you did something to make a lot of people very angry at you.
Recipients Who Liked on Facebook
If you included a Like Button on your campaigns, we'll show you how many people and who on your list Liked your campaign.