OME link expiry

Hi,

Been searching and looking through the official documentation but can't find any information regarding the link expiry that's in the message :  "This link will expire on May 12, 2018"

I can still open the message so it doesn't seem to have expired and it doesn't seem to be a setting for the expiration date... Does anyone know if the messages does expire and if there is a setting for how long it should be accessible?

Br

Mattias