Google it seems is always looking for ways to improve the security of their services, including Gmail. Email is probably one of the most used services for most people connected to the web, and Google wants to make things a little bit safer for its users by introducing a new warning system to alert people of dangerous incoming emails. These security updates to Gmail will take around three months or so to roll out to users, but once Google deploys these changes the new warning system will be able to alarm people if they receive emails that are unencrypted when coming from non-Gmail email clients.
While the changes outlined here are aimed at aimed at alerting users to users to unencrypted emails, (although this isn't an issue with Gmail to Gmail since everything is already encrypted) which are still very much a problem for emails coming in from users that are sending from outside clients, Google states that since 2013 up to now, the rates of non-Gmail emails being sent in with encryption to Gmail users has risen by a total of 28%, going from 33% to 61%. This is definitely good new for those who choose to use Gmail as their client of choice for handling emails, but there is still always some work to be done.
In this regard, Google details some specifics on hurdles they're working to overcome to better the security and privacy of email for their users. Thanks to a study between Google, the University of Michigan, and the University of Illinois that looked at the evolution of email security from 2013 to 2015, Google was able to discover a security risk that actively tries to block email messages from being encrypted through manipulation of SSL requests. Another potential threat uncovered by the multi-year study were malicious DNS servers that attempt to purposely feed incorrect information, so that they might be able to manipulate the email messages, either by censoring particular pieces of information within the email, or by altering pieces of information altogether, before the user who the email is meant for has a chance to see it in its original, unaltered state.