There's some significant weirdness in this. 'team@trubrain.com' is currently a digest-mode subscriber to this mailing list.
TruBrain, found online at Learn.TruBrain.com, is a company that promises people access to “focus drinks,” said to help people with mental cognition, delivered directly to their door each month.
http://www.reviewopedia.com/trubrain-reviews
https://trubrain.com/pages/contact lists 'team@trubrain.com' as a role contact address.
The referenced 'https://trubrain.freshdesk.com/register/eI5do3Ps3KFRepKr0VPh' URL provides the ability to 'Activate your freskdesk account' for user 'Balug-admin'.
I don't know exactly what set this situation up, but I think this is badness and therefore just now removed subscriber team@trubrain.com from this mailing list.