To allow people to search for your email, simply redirect https://youremaildomain/.well-known/webfinger to https://webfinger.io/.well-known/webfinger and it'll work.
We've taken several steps to ensure this service is safe and respects users privacy. We only ask for the data you want us to serve (your email and Mastodon ID). We support email addresses deleting their record, and marking themselves as "do not contact". We also support administrative blocklists for both emails and Mastodon IDs, e.g. we can block "example.org" if you do not want your users to use this service, contact us at admin at webfinger.io. We also restrict the length and format of emails and Mastodon IDs to 128 characters. This service runs on Cloudflare Workers and KV store, and uses Mailchannels to send the emails. These providers log data such as IP addresses accessing their service and the email address of email sent.
webfinger.io is a Cloud Security Alliance Research project. It is available in GitHub at https://github.com/cloudsecurityalliance/webfinger.io.