Tested the sanitization redaction feature recently on a Mac, using PDFs exported from the Mail.app email program. Noticed that any document exported from Mail.app would end up missing its individual letters i and l (lowercase L) every time.
This includes combinations of the letters i and l as well.
gmail.com becomes gma .com
flipping becomes f pp ng
Digging a little deeper, I backed off the sanitization feature and used Acrobat to find hidden information. Discovered that these letters are consistently considered hidden text with the Helvetica font. Here's the typical pattern of identified hidden text:
i li il i i i i li i li il
I'm able to replicate the problem every single time I sanitize something from the Mail.app application. Helvetica is used as the font for the header detail in each and every email in the Mail.app application exports to PDF, and that particular font can't be changed in the Mail.app preferences (body text can but not header text).
Anyone else experiencing this problem? Using Acrobat DC 2015.016 and Mail.app 9.3 at the moment.