GitLab does not accept @vfemail.net email addresses even though they're OK

Summary

I tried to set my @vfemail.net email address as my default GitLab email address. I am able to add the address to my account, but not as the main email address (I currently use it as my public email on my profile). Currently, I use my @openmail.cc address for my account, which is an alias for my VFEmail inbox, and is one of the email domains that belong to the VFEmail provider.

Steps to reproduce

Have an @vfemail.net email address, add it to your GitLab account and try to set it as your main email address.

Example Project

What is the current bug behavior?

I receive an error message on the GitLab website telling me the email address is invalid and I should "use my own email". Presumably, GitLab thinks VFEmail is one of those disposable address providers, like 10minutemail, etc.

What is the expected correct behavior?

I should be able to set my @vfemail.net address as my main email address, as it is a regular, valid, permanent email.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of: sudo gitlab-rake gitlab:check SANITIZE=true)

(For installations from source run and paste the output of: sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)

(we will only investigate if the tests are passing)

Possible fixes

Edited by Ghost User