Changes: https://www.mozilla.org/thunderbird/52.5.2/releasenotes/ Security: https://hg.mozilla.org/releases/comm-esr52/rev/01f2c40a0ce9 Security: https://hg.mozilla.org/releases/comm-esr52/rev/6c35468148bb Security: https://hg.mozilla.org/releases/comm-esr52/rev/67c559a7ffee Security: https://hg.mozilla.org/releases/comm-esr52/rev/8bc93e746d82
