Comment Law Enforcement Forensics (Score 1) 601
Sadly, part of the reason for people not encrypting their email is that they believe all encryption standards to be broken. Having seen several forensic analysis software suites with options to decrypt PGP, I doubt PGP's effectiveness in keeping out unwanted eyes. I wish this were not the case. I am aware of the many news stories where encryption was hailed as preventing evidence from being gathered but I doubt that just the encryption was the problem.
On the one hand you have the fact that encryption is not integrated into email for everyone, and the other you have the lack of trust in a truly unbreakable encryption standard. You'd need both to happen to convince the masses to switch to encrypted emails.