Google has doubled the size limit for attachments on the emails received, from 25MB to 50MB. Although we already have Google Drive to share the big files, but with this update, users will now be able to at least receive attachments as big as 50MB.
However, the sending size limits remains at 25MB, which means you still can not send files which are larger than 25MB in size. So if you try to send more than 25MB worth of attachments in one go, you will be prompted to upload files to Google Drive and share them through the cloud storage service instead.
According to this blog post by Google, the update will be activated from today.
