Fixes CVE-2020-{27216,28007,28008,28009,28010,28011,28012,28013,28014,28015, 28016,28017,28018,28019,28020,28021,28022,28023,28024,28025,28026}. See the upstream security advisory for more information: https://exim.org/static/doc/security/CVE-2020-qualys/21nails.txt * gnu/packages/mail.scm (exim): Update to 4.94.2.