Salmon, a Python Mail Server

https://salmon-mail.readthedocs.io/en/latest/

by tosh • 8 years ago

214 52 8 years ago

salmon-mail.readthedocs.io

pecg• 8 years ago

I can't understand the reasoning on putting everything behind HTTP these days. Personally, I think that if a project decides to go that route it's because poor design decisions. Separation of interests should exist in software solutions.

nantes• 8 years ago

Where does it say that it sits behind HTTP?

The only bit I see that talks about something similar is, "Salmon is designed to sit _behind a traditional mail server_ in the same way a web application sits behind Apache or Nginx", emphasis is mine.

rubinelli• 8 years ago

It would be nice if the documentation had some examples of how to do that, though. All it says is this:

Salmon is best deployed behind another mailserver such as Postfix or Sendmail - much in the same way as you host a WSGI application behind Apache or Nginx.

adiusmus2• 8 years ago

Lots of tools for interacting with services via http. Curl, urllib, SOAP etc etc.

Node.js / Python both have very good support for http. Soap etc, run a web server for quick file serving from command line if you want. Dgraoh and other tools can easily be interfaced via http.

Why not leverage all that?

dec0dedab0de3• 8 years ago

It is a combination of developers wanting to have cross platform end users, while also working around restrictions in place on corporate networks. It's been downhill since hotmail.

mendeza• 8 years ago

Looks interesting! What are common use cases to use this kind of library? I was thinking of using it to automate uptime of servers or exploring adding NLP to emails, but I am interested what are popular uses for this kind of a framework.

Arkdy• 8 years ago

Turns out that sending mail is pretty straightforward, but receiving is messy.

I was evaluating it for the use case where I needed to receive emails, and then respond based on the user's position in a decision tree.

wpietri5• 8 years ago

That seems an odd omission, in that sending mails is easy whether or not you have a custom server.

nikkaelle3• 8 years ago

I use salmon's predecessor (lamson) to process emails for an email-driven helpdesk system. Emails come in through lamson, are processed based on headers, and either attached to the support ticket they belong to or are routed to an admin for manual processing.

Lamson isn't a perfect fit for the system, but it did make it easy to get started. Unfortunately it also had a number of bugs I had to fix, since the project was defunct. I should check to see if salmon needs those fixes.

greglindahl2• 8 years ago

The traditional way to do this is using software like procmail -- can you comment on what lampson/salmon does better than procmail for your use-case?

adiusmus2• 8 years ago

Looks interesting. I could finally automate the FAQs I receive on regular basis. Like mail filters with a template engine.

u801e• 8 years ago

Could Milters[1] be used to do a lot of what Salmon does?

[1] https://en.wikipedia.org/wiki/Milter

zrail• 8 years ago

Yes, but milters are not much fun to write. Postfix has a way to use a sidecar MTA (like lamson/salmon) to filter. Effectively Postfix passes the mail to the external process via SMTP and then, if the process chooses to, it can re-inject the message into a queue in Postfix.

I worked on a system years ago that did this for FBL reports.

meredydd• 8 years ago

If you're looking for something like this, but without setting up postfix/sendmail yourself, Anvil has a pretty straightforward API (and it's already hosted on a domain):

https://anvil.works/blog/email-driven-apps

(There's a video example at that link, where I build and deploy a Mailinator-like service from scratch in a couple of minutes.)

L_Rahman• 8 years ago

I respect your continued push for Anvil. I see your comments on threads from time to time and even though you're promoting your own product it feels topical and appropriate.

rapfaria• 8 years ago

We do live in the "shameless plug" era.

wpietri5• 8 years ago

From the page, some open-source drama:

Salmon is a fork of Lamson. [...] Lamson was relicensed under a BSD variant that was revokable. [...] I read that to mean that I could make a contribution but then have said work denied to me because the orginal author didn’t like the colour of my socks. So I went and found the latest version that was available under the GNU GPL version 3.

Does anybody know the backstory here?

m_eiman• 8 years ago

I know that Zed Shaw wrote Lamson, but I know nothing about the drama.

dna_polymerase• 8 years ago

I don't think there was some drama between two people involved but the creator of salmon was afraid his license of Lamson could be revoked someday, just as the license states. In order to avoid this he forked an earlier version.

mygo• 8 years ago

good on him. there’s not many things to fear in this world but the prospect of someone having you by the balls is definitely one of them.

well, unless you’re into that

dec0dedab0de3• 8 years ago

No, but the clause in that license is gross. He can sue any of his users at any time if he decides he doesn't want them to be his users anymore. It's by Zed Shaw author of Learn Python the Hard Way, I'm surprised by this. In any case it looks like Lamson has not been updated since 2013.

The clause:

The copyright holder reserves the right to revoke this license on anyone who uses this copyrighted work at any time for any reason.

drharby• 8 years ago

I didnt think infinity wars was THAT good.

REVOKED!

dragonwriter3• 8 years ago

Ironically, that clause might have no effect in US law; not because a license with it fails to be revocable, but because gratuitous licenses are revocable at will as a matter of law, anyway.

(Then again, it might mitigate the likelihood that a court would limita the licensors recovery after revocation based on the principle of promissory estoppel.)

hellosputnik• 8 years ago

Why are you surprised? Zed Shaw is notorious for being belligerent.

ianwalter4• 8 years ago

I bet I'm going to get downvoted for this, but how is this gross? It's his work. He should be able to license it however he wants. If you are worried about him revoking the license then don't use it. He's under no obligation to provide you with software.

https://zedshaw.com/archive/why-i-algpl/

carlosperate• 8 years ago

Not the backstory, but some background: https://news.ycombinator.com/item?id=4242786 https://github.com/moggers87/salmon/issues/8

nicolaslem• 8 years ago

It reminds me of slimta[0], a Python framework for building Mail Transfer Agents. I used it to run some custom code to detect SPAM characteristics of incoming emails.

[0] https://github.com/slimta/python-slimta

href• 8 years ago

Thank you! I want to implement an e-mail gateway for our web application that fans out e-mails to various commercial MTAs and this seems like it would be a useful building block for that.

andris9• 8 years ago

Lots of interesting things happening in email development recently. I would compare it with ZoneMTA that is a component in WildDuck, a full featured email server written in plain node.js (https://wildduck.email)

markovbot• 8 years ago

Wow, wildduck looks super interesting. I would try it right now if it didn't require mongodb

lewis1028282• 8 years ago

Salmon is written entirely in Python and runs on Python 2.7 with experimental support for Python 3. It should hopefully run on any platform that supports Python and has Unix semantics.

Why!?

twistadias• 8 years ago

>Python versions supported are: 2.7, 3.5, and 3.6.

From the docs

niftylettuce• 8 years ago

If you need a free/encrypted/open-source email forwarding service w/o having to set anything up - see https://forwardemail.net

blackrock• 8 years ago

Nice, I always wanted to write a mail server.

Is there any design documents? The stuff to explain the design, architecture, motivations, and intent.

rav• 8 years ago

I've used the GPL3 version of Lamson in the past - nice to see that someone continued development on that version in a fork.

I have since switched over to aiosmtpd [1], a Python 3 based SMTP server using asyncio that was developed by Barry Warsaw and friends.

[1] https://aiosmtpd.readthedocs.io/en/latest/

Salmon, a Python Mail Server

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