Samotop

SMTP Relay Server (MTA) library and a sample simple server implemented in Rust with focus on spam elimination and privacy. The motivation is to revive e-mail infrastructure and architecture, address current problems and allow new systems to integrate SMTP. It's called SaMoToP, which could be a nice Czech word.

Status

We've got a decent SMTP command parser written as a PEG grammar. The model is tightly nit from the RFCs. A tokio based server will hear your SMTP commands, drive the SMTP state machine and correct you if you step aside. Once a mail session is ready, the mail data are streamed to the console. After that, you can do it again.

Todo

• Successfully parse a simple SMTP session
• SMTP state machine - helo, mail, rcpt*, data, rset, quit - must be in correct order
• DATA are handled and terminated correctly (escape dot, final dot).
• Simple SMTP MTA, logging smtp session to standard output but able to receive mail from common relays
• Privacy: STARTTLS required
• Antispam: Strict SMTP
• Antispam: whitelist and blacklist
• Antispam: greylisting
• Antispam: white/black/grey list with UI - user decides new contact handling
• Antispam: DANE (DNSSEC) with UI - user verifies signatures
• Antispam: SPF
• Processing: Relay mail to another MTA
• Processing: Store mail in Maildir (MDA)
• MDA: User mailbox - mailbox for specific address or alias
• MDA: Domain mailbox - mailbox for unclaimed addresses
• MDA: Smart mailbox - multiple mailbox addresses by convention
• MDA: Sieve
• Privacy: Encrypted storage
• Privacy: No trace

Company

In Rust world I have so far found mostly SMTP clients.

• lettre is an SMTP client, it seems to be alive and well!
• segimap by uiri, that's actually an IMAP server.
• rust-smtp by mneumann, last commit 2014, parser coded manually, looks unfinished and abandoned.
• rust-smtp fork of the above with progress by synlestidae in 2016
• ferric-mail by wraithan, looks abandoned since 2014.