[JAMES-3819] [GSOC] James as a (distributed) MX server

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: SMTPServer
• Labels: gsoc gsoc2023 part-time
• Assignee: Unassigned
• Reporter: Benoit Tellier
• Created: 23/Sep/22 03:24
• Updated: 09/Feb/23 13:52

Description

Why ?

Alternatives like Postfix...

• Do not offer a unified view of the mail queue across nodes
• Requires statefull persistent storage

Given Apache James recent push to adopt a distributed mail queue based on Pulsar supporting delays (JAMES-3687), it starts making sense developing tooling for MX related tooling.

I propose myself to mentor a Gsoc on this topic.

Benefits for the student

At the end of this GSOC you will...

• Have a solid understanding of email relaying and associated mechanics
• Understand James modular architecture (mailet/ matcher / routes)
• Have a hands-on expertise in SQL / NoSQL working with technologies like Cassandra, Redis, JPA...
• Identify fix and solve architecture problems.
• Conduct performance tests and develop an operational mindset

Inventory...

James ships a couple of MX related tools within smtp-hooks/mailets in default packages. It would make sense to me to move those as an extension.

James supports today...

checks agains DNS blacklists. `DNSRBLHandler` or `URIRBLHandler` smtp hook for instance. This can be moved as an extension IMO.

We would need a little performance benchmark to document performance implications of activating DNS-RBL.

Finally as quoted by a gitter guy: it would make more sens to have this done as a MailHook rather as a RcptHook as it would avoid doing the same job again and over again for each recipients. See JAMES-3820 .

Grey listing. There's an existing implementation using JDBC as an underlying storage.

Move it as an extension.

Remove JDBC storage, propose 2 storage possibilities: in-memory for single node, REDIS for a distributed topology.

Some work around whitelist mailets? Move it as an extension, propose JPA, Cassandra, and XML configured implementations ? With a route to manage entries in there for JPA + Cassandra ?

I would expect a student to do his own little audit and come up with extra suggestions!

Issue Links

• is related to: JAMES-3820 DNS Blocklist: implement DNSRBLHandler as MailHook instead of RcptHook

Sub-Tasks

• Implement RFC-8689 RequireTLS: Open
• Simple Mail Transfer Protocol Extension for Message Transfer Priorities: Open
• IP filtering with CrowdSec: Open