I’ve placed the following rewrite rule in the .htaccess file for the
‘hq.swimisca.org‘ subdomain:
RewriteEngine on
RewriteCond %{REQUEST_URI} !^.well-known/
RewriteRule (.*) https://swimisca.org/ [R=301,L]
This will redirect all HTTP/HTTPS requests for ‘hq.swimisca.org‘ to
‘https://swimisca.org/‘, *except* those made by the Let’s Encrypt
validation server for the renewal of the SSL certificate. You may create
any mailboxes you wish to have on the subdomain now.
Please let us know if there is anything else we can do for you.