IMAPFilter through 2.6.12 does not validate the hostname in an SSL certificate.
lists.opensuse.org/opensuse-security-announce/2020-05/msg00042.html
lists.opensuse.org/opensuse-security-announce/2020-06/msg00002.html
bugs.debian.org/939702
github.com/lefcha/imapfilter/issues/142
lists.debian.org/debian-lts-announce/2019/10/msg00040.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GBNDFMAIUA6PQMV2P6OKIP7JZQEWX7D2/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IQUH2TOCNEST7JB2RJVVJT3RZS5XZCFZ/