According to https://bugzilla.mozilla.org/show_bug.cgi?id=281219 the "Show items that contain" is for Newsgroup use but disabled for IMAP rather than hidden. In my opinion a minor bug that may cause confusion but the implication from the bug report is that the Subscribe dialog has been designed that way. Bug report ongoing for 14+ years so an issue that may never be fixed.
** Bug watch added: Mozilla Bugzilla #281219 https://bugzilla.mozilla.org/show_bug.cgi?id=281219 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/912706 Title: 'Show items that contain' disabled in subscribe dialog To manage notifications about this bug go to: https://bugs.launchpad.net/thunderbird/+bug/912706/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
