This is a known problem with the way email attachments are treated. PDF files are frequently treated as ascii files, when they need to be treated as binary files. The corrupt can occur anywhere along the path from you to the recipient. There are two ways to handle the problem. You can compress the files (like zip), before attaching. The drawback is that it takes an extra step and some organizations ban compressed attachments. You can post the file on an internet based server and send the recipient a link to the file. This takes an extra step by you and the recipient and you have to have a server that both you and the recipient trust.
Hi Michael, Thanks for the response. We have been sending 1000's of pdf's for several years with no problem at all. It's only of the last 6 - 8 weeks that the problem has occured. If I send the same file to the same person at the same email address 3 times in the space of 2 minutes 1 or 2 out of the 3 can be corrupted or at another time all three arrive and open perfectly. Surely if it is the reason you said, it would apply to all of the files.
Kind regards, Mark.
I've also recently discovered this happening with multiple page PDFs I've been emailing my clients. All pages except the second page seem to be fine--the second page being corrupted.
I too did not have this issue until (first noticed anyway) a month or two ago (however in our thread's timeline, others have posted in 2012 and I'm posting this on June 19, 2013.
I appreciate MichaelKazlow's comments and suggestions and will try that route (creating zip files).
I was also wondering though, if upgrading to Apple's Mountain Lion (10.8.4) OS might have anything to do with it (certainly not for the previous posters). Or if changes in updated versions of Adobe Acrobat Pro could do it. If it's merely caused by what MicahelKazlow explained, I'm curious why I've never had this issue before recently. And the same for Mark.
Also as Mark; sometimes a recipient will get all pages intact, while lately most recipients continue asking me to resend them the second page. So it's either random, or email clients (or computers/operating systems) possibly treat these attachments differently (?).
Email attachments are never 100% safe; they can get damaged or lost during transmission.
Far safer is to use a file sharing service (like Acrobat.com, Dropbox, Google Drive, ...), then send the shared link to the document by email. This will also get you around size limitations imposed by email servers.