samotop-server 1.1.0

You can run your own privacy focussed, resource efficient mail server. Samotop docker image is available for your convenience.

Status

General

• Tiny docker image - only contains statically compiled samotop and openssl, no OS clutter.

Common (MDA/MTA/MSA)

• The server will receive mail and write it to a given maildir folder. Another program can pick the folder and process it further.
• STARTTLS can be configured if you provide a cert and identity file.

Mail delivery agent (MDA)

• Encryption at rest
• Accounts
• LMTP
• Sockets

Mail transfer agent (MTA)

• Mail relaying
• Antispam features:
  • SPF - refuse mail with failing SPF check
  • Greylisting

Mail submission agent (MSA)

• Authentication

Installation

• Using cargo:

  cargo install samotop-server
  

• Using docker:

  docker pull brightopen/samotop
  

Usage

• locally, run samotop-server --help for command-line reference.
• 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

TLS

You can run these openssl commands in docker as well. This will run an openssl with the current folder mounted under /data and that is also the work dir:

docker run --rm -ti -v "$PWD:/data/" -w "/data/" --entrypoint openssl samotop help

Generate a cert and ID with openssl:

openssl req -new -newkey rsa:4096 -x509 -sha256 -days 365 -nodes -out Samotop.crt -keyout Samotop.key

Test STARTTLS:

openssl s_client -connect localhost:25 -starttls smtp

Debug with STARTTLS:

openssl s_client -connect localhost:25 -debug -starttls smtp

Other useful hints for TLS

For native-tls, you'd convert to pfx:

openssl pkcs12 -export -out Samotop.pfx -inkey Samotop.key -in Samotop.crt

Extracting pub key from cert:

openssl x509 -pubkey -noout -in Samotop.crt  > Samotop.pem

License

MIT OR Apache-2.0

Contribution

Unless you explicitly state otherwise, any contribution submitted for inclusion in samotop projects by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.