I used to email myself some .epub files (using Gmail), and then on the iPad, in the email program, click on the .epub file and then choose to open in iBooks, and read, highlight, and add notes to the ebook. What is amazing is that all the highlighting and added notes will sync across my iPad and iPhone whenever I have the same .epub file on that device.
However, recently, I tried doing the same for the new iPad (3rd Gen), but it can download the .epub file alright, showing it as 5.5MB, but when I click on that file after the download, it won't ask me to open in iBooks any more (and won't open anything or ask what application to open it).
Is there a way to solve this (or is this a bug). Can Dropbox or Box.net solve this? Although, it is best if email can be used, because then not additional app is needed besides email which is always there. (I label the email as "ebooks" using Gmail's label function, so that all the files can be easily listed out of thousands of emails).
Best Answer
This feature hasn't been changed in iOS, so either the mail transport or client isn't faithfully preserving the file or you iOS device has issues and needs to go through troubleshooting.
If you have a second device, you could test setting up your mail account and see if it's a temporary (or permanent) mail issue.
Otherwise, you'll need to work on narrowing down why your device isn't working as expected.