FetchPop

A personal app to automate bulk operations on a POP3 email account.

Under MIT License.

There's more on the wiki.

State Of Play

Refactoring into a test-driven object-oriented application guided by end to end tests from a legacy script.

Usage Notes

Based around the idea of a series of operations. Each operation is an isolated session.

Pass the name of the operation on the command line as no-argument options. For example

java -jar ~/source/fetchpop/target/fetchpop-app-0.0.3-SNAPSHOT.jar status

Operations

Name	Function
status	Connects to the POP3 server, asks for status and then logs to console.

Use Cases

GH-14 Debug Profile

As a User

I want a profile with full debugging logs

Activate profile debug to log debugging to console

java -jar -Dspring.profiles.active="debug" fetchpop-app-0.0.1-SNAPSHOT.jar

GH-2 Operation - Print Status

When I perform a PrintStatusOperation Then the number of messages and message box size should be output

Output should be printed main logger. See Quiet Profile.

GH-1 Quiet Profile

As a User

I want a profile consistent with UNIX output standards

By default, FetchPop is Spring-Boots-esque and logs to console.

Activate profile quiet to suppress

Implemented using Logback markers.

GH-5 Set Account Details

As a User

I want To Set Account Details

GH-4 Debug Low Level Commands

As a Diagnoser of Problems I want to see low level communication

Apache Commons Net supports listening for low level communications. These messages are printed to the special logger named "protocol".

GH-30 Plain Text

To enable smoke testing and edge cases, setting application.host.tls to false will force plain text connection.

application:
  user: alice
  cred: Rabbit
  host:
    name: localhost
    port: 110
    tls: false

GH-29 Docker Smoke Container

It's often inconvenient to play around against a live email server. The container in the smoke directory describes a docker image that runs a POP3 server with user alice password rabbit and some sample emails.

To build and run this server:

$ cd smoke
$ docker build -t pop3server .
$ docker run -p110:110 pop3server

To connect, use

application:
  user: alice
  cred: Rabbit
  host:
    name: localhost
    port: 110
    tls: false

A profile has been set up called smoke which allows Status (for example) to be run as follows:

mvn spring-boot:run -Dspring-boot.run.profiles=smoke,debug -Dspring-boot.run.arguments=Status

GH-29 Print Message Info

This fetches header information for messages and prints key headers to standard output.

Sample Use Cases

• Assess the contents of a mailbox before archiving

For example

mvn spring-boot:run -Dspring-boot.run.profiles=smoke,quiet -Dspring-boot.run.arguments=Info

might output

From: John Doe <jdoe@machine.example> Message-ID: <1234@local.machine.example> Subject: Saying Hello
From: "Joe Q. Public" <john.q.public@example.com> Message-ID: <5678.21-Nov-1997@example.com>
From: Pete <pete@silly.example> Message-ID: <testabcd.1234@silly.example>
From: Mary Smith <mary@example.net> Message-ID: <3456@example.net> Subject: Re: Saying Hello

GH-35 Bump Dependencies

Upgrade dependencies including spring boot to 2.3.4 and Java to LTS 11

Key Technologies

• Apache Commons Net
• Spring Boot

Configuration

Spring Boot standard application properties. Users are encouraged to use custom profiles.

Example Command Line

java -jar -Dapplication.user="POP3 User" -Dapplication.cred="POP3 passwd" -Dapplication.host.name="POP3 Server Host Name" -Dapplication.host.port=999 fetchpop-app-0.0.1-SNAPSHOT.jar

Example YAML

Save

application:
  user: me@example.org
  cred: ABCDEF
  host: 
    name: pop3.example.org
    port: 999

as config/application-account.yml

Then run

java -jar -Dspring.profiles.active="account" fetchpop-app-0.0.1-SNAPSHOT.jar

Features And Fixes

Just pre-releases for personal use.

Next Release

• GH-35: Upgrade dependencies

0.0.4

• GH-28: Print Message Info
• GH-29: Docker POP3 smoke server
• GH-30: Allow plain connections through configuration

0.0.3

• GH-25: Spring boot console app with status
• GH-23: Upgrade to Spring Boot 2
• GH-21: Warn when account data not set

0.0.2

• GH-19 Add Debug Profile
• GH-4 Debug protocol comms
• GH-2 Status command

0.0.1

• GH-1 Add Main Logger
• GH-5 As a User I want To Set Account Details

Rationale

Though the Java community seems to produce fewer command line utilities than Ruby or Python (say), Java has unexploited advantages. Technologies such as Spring Boot

A Spring-esque Command Line

This is a Spring-esque command line app. It has few aspirations to be Unix-esque, Ruby-esque or Python-esque, grand as those approached undoubtedly are.

Why Spring Boot...?

• Reduced boiler plate
• Easy creation of executables
• Advanced end to end tests with minimal boiler plate

In this case I'm relaxed about

• Lots of dependencies
• Bigger executable

Apache James FetchPop Limitations

For many years, I ran a local personal fork of Apache James. Key features

• Efficiently serve over IMAP mail originally delivered to many accounts beyond the limits of clients like Thunderbird to cache locally;
• Full access to archives even when machine is offline;
• Advanced filtering using SIEVE;
• Portability, able to zip and relocate;
• Mail accessed via POP3

But the James FetchPop implementation has known limitations. Would need a complete refactor and proper modularization. After my injury

• not reasonable to ask myself to make the time to drive this approach through a community based process;
• unable to run personal Apache James server for a few years building up a major backlog.

Finely Grained Exceptions

This app throws finely grained exceptions to allow precise diagnosis even at statistical scale. Probably a little much but the habit's good.

A Little Note

This is a personal app. Made by me, for me to scratch a personal itch. Make of it what you will.

Please don't expect me to undertake unpaid development on it for you.