Contacting administrators of debian mirrors

I recently discovered issues with several public mirrors listed on
debian.org and tried to get into contact with their administrators, but I
was only able to find plausible email addresses for 2 out of 5 mirrors. Is
there a standard way to get this information? Alternatively, can someone on
this list get in contact with the mirrors below?

Details on the issue:

I have a CI build that (among other things) sets up a stretch image and
tries to install some packages on it. For some time now it has been
sporadically failing to download and verify gnome-user-guide version 3.22.0
(available at
/pool/main/g/gnome-user-docs/gnome-user-guide_3.22.0-1_all.deb). The CI
system uses the CDN at deb.debian.org to pick a mirror, so there wasn't any
easy way to find the source of the corrupted package and eventually I
decided to just check all the public mirrors for this file and see who's
version differed. Note that I *only* checked this one file, there is every
possibility that there are more corrupt files on these or other mirrors.

http://ftp.acc.umu.se/debian/
Contacted [email protected] per the footer message on each page
This appears to be the primary mirror for both Finland and Sweden

http://ftp.mpi-sb.mpg.de/pub/linux/debian/
Contacted [email protected] per the instructions at
https://ftp.mpi-inf.mpg.de/pub/welcome.msg

http://debian.uvigo.es/debian/
Uncontacted

http://mirror.i3d.net/debian/
Uncontacted

http://mirrors.pardisco.co/debian/
Uncontacted