Trusted device and activation email never received when first time login

Hi there,

Hoping for some assistance on my user who just received Teamviewer access under our corporate license user management. As info, I'm one of administrator for the account. So when my user login with the user name and password I provide to her but unfortunately she unable to get any email of activation & trusted devices even there is message appear saying please wait for the email coming to user email inbox. User already tried few times but nothing coming in.

Hope for some solution for this issue.

Thanks.
Hafiz