Hi @StarGroup , Not sure off the top of my head if the Meraki default splash page has that capacity but there are third party solutions that you can integrate with which will work and provide you so much more than just an email address.
I.e - Purple Wifi - https://purple.ai
Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.