Sometimes a mail , according to the report, has been opened many many times e.g. 24. It is often in the space of a few minutes.
Is it due to the recipient having a viewing pane for their emails and flicking through their emails?
We've just had a client of ours question the exact same issue too (1 person apparently ended up opening an email 1251 times!). I have put a question to the guys in support.
Not had a response from Support yet, but found some other Forum posts that seem to help explain our high open rates:
Sorry for the delayed response. We sometimes see this happen when, as you discovered in those two links, a recipient is using a preview pane in their email reader. A subscriber could have a "Preview Pane" feature enabled in his or her email client. In this case, every time the campaign email was clicked or scrolled to in the "Preview Pane", and the images are downloaded, the subscriber's address displays as having opened the campaign. You might have a look at this link in help: http://help.campaignmonitor.com/topic.aspx?t=62
Also, the instance of a subscriber forwarding the email on to a bunch of other people, can affect the opens. Each one of those people opening it would appear as an additional open for the original subscriber (those open/clicks are attributed to the original recipient).
A rarer occurrence though, but a person could have a virus protection on their computer that continues to scan the links in the email (if the preview is left open, the anti-virus software might scan every 10 min - leaving the pane open), essentially producing a huge number of opens in an inhumanly short amount of time (1200 opens could be from this). Thanks!