Mail statistics are generated while avoiding all uses of intrusive trackers, especially to protect users privacy and avoid collecting information that could help build a comprehensive list of all mailu setups.
To accomplish this, Mailu uses DNS and relies on the fact that the vast majority of servers do not run a local resolver but rely on recursors instead, thus masking the true originating address from a query.
Unless the admin disables statisics upload in the configuration, Mailu instances run a DNS query (try and download a HTTP URI) for a name composed as follows:
<version>.<instanceid>.stats.mailu.io
The version is the Mailu version string. The instanceid is a unique id persisted per instance, stored in a file next to the main database. instance ids are UUIDv4.
The statistics server stores the timestamp, version and instance id everytime it receives a request.
If you use Docker, getting it running to serve stats.mailu.io is very easy:
docker build -t mailu-stats --rm .
docker run -p 53:53/udp -it --rm --name mailu-stats mailu-stats
All environment-variables listed below can also be set in Docker via the -e/--env flag:
docker run -p 53:53/udp -it -e DOMAIN=stats.mydomain.com --rm --name mailu-stats mailu-stats
If you want to build the service manually you should set some environment-variables, here is a list of all, their defaults and what's their purpose:
| variable | default value | purpose |
|---|---|---|
| LOGPATH | /output.log |
where to store the log |
| HOST | 0.0.0.0 |
which IP or Hostname to listen on (supports IPv4 and IPv6) |
| PORT | 53 |
which port to listen on |
| DOMAIN | stats.mailu.io. |
which domain we serve. MUST end with a dot! |
| VALUECOUNT | 2 |
how many subdomains (=values) we want |
And then you can simply build and run it with:
go build -v
./Stats