The possibility to proof the student's or teacher discount does not work

I got an e-mail that my teacher education discount is expireing and that I have to confir teacher’s status to still use it. I do not have an e-mail ending on “edu”. 

When I click the link provided in the e-mail I see this error message: 

When I click the link in my account that looks like this: 
 

I get another error message: 
 

I still work for the univerities and in the organisation that provides education as a teacher. Can I do something about that? What do those messages mean? Can send somewhere a proof like a contract, that I work for the university with my name on it? 

What should I do? 

Best regards, 
Zuzanna Wiśnicka Tomalak