Google has reportedly made Gmail mandatory, removing ability of users to opt out of the feature.
It has been four years since the search giant turned on HTTPS by default in Gmail, but until now, had allowed users to not use encryption.
The company had explained back then that the opt-out feature was necessary as encryption could make the mail slower, Cnet reports.
A Google spokesperson said that the team had been working hard to mitigate any performance costs, which now puts us in a position where it no longer makes sense to allow HTTP connections.
Post revelations by whistleblower Edward Snowden, Google implemented a measure that encrypted Gmail messages internally, as they move about Google's servers and data centers, the report added.