You can run your own privacy focussed, resource efficient mail server. Samotop docker image is available for your convenience.
a) Using cargo:
bash
cargo install samotop-server
b) Using docker:
bash
docker pull brightopen/samotop
a) locally, run samotop-server --help
for command-line reference.
b) in docker, run docker run --rm -ti samotop
Both should produce a usage information not too different from this:
samotop 1.0.1
USAGE:
samotop-server [FLAGS] [OPTIONS] --cert-file <cert file path> --identity-file <identity file path>
FLAGS:
-h, --help Prints help information
--no-tls Disable TLS suport
-V, --version Prints version information
OPTIONS:
-n, --name <SMTP service name> Use the given name in SMTP greetings, or if absent, use hostname
-b, --base-dir <base dir path> What is the base dir for other relative paths? [default: .]
-c, --cert-file <cert file path> Use this cert file for TLS. If a relative path is given, it will be
relative to base-dir
-i, --identity-file <identity file path> Use this identity file for TLS. If a relative path is given, it will be
relative to base-dir
-m, --mail-dir <mail dir path> Where to store incoming mail? If a relative path is given, it will be
relative to base-dir [default: inmail]
-p, --port <port>... SMTP server address:port, such as 127.0.0.1:25 or localhost:12345. The
option can be set multiple times and the server will start on all given
ports. If no ports are given, the default is to start on localhost:25
Generate a cert and ID with openssl:
bash
openssl req -new -newkey rsa:4096 -x509 -sha256 -days 365 -nodes -out Samotop.crt -keyout Samotop.key
Test STARTTLS:
bash
openssl s_client -connect localhost:25 -starttls smtp
Debug with STARTTLS:
bash
openssl s_client -connect localhost:25 -debug -starttls smtp
MIT