Version 1.8-1 of wordpress-shibboleth is marked for autoremoval from testing on Tue 08 Jan 2019. It depends (transitively) on libphp-phpmailer, affected by #905254. You should try to prevent the removal by fixing these RC bugs.
The current maintainer is looking for someone who can take over
maintenance of this package. If you are interested in this
package, please consider taking it over. Alternatively you may
want to be co-maintainer in order to help the actual
maintainer. Please see bug number #796960 for more information.
Last update: 2017-12-02
Standards version of the package is outdated.
The package should be updated to follow the last version of Debian Policy
(Standards-Version 4.2.1 instead of