I am trying to configure the outgoing mailserver in my odoo 15 community instance, but i cannot get it to work!

Here is the configuration i am using

i use the email service from one . com and this is the information they provide for SMTP:

i am using the correct password and username in odoo. What am I doing wrong / is missing?

When i click on test connection odoo gets stuck at the loading screen like this forever:

after a while i get the following error:

Verbindungstest fehlgeschlagen! Hier sehen Sie, was wir an Stelle dessen bekommen haben: 101 Network is unreachable

Network is unreachable