The mail settings in the VCSA65 environment is grayed out and no edit button as well.
I checked this KB article "https://community.spiceworks.com/topic/2306519-vmware-6-5-smtp-settings-in-html5-web-client" but didn't help.
Can you assist me
you mentioned you have vCenter 6.5
I don't know if there were no limitations to such an option. In case after the restart, you will not be able to edit - upgrade to 6.7
You just win from the upgrade only.