Pop3mail

Pop3 client to download email (including attachments) from the inbox via the commandline or Elixir API.
Written in Elixir, using an Erlang pop3 client with SSL support derived from the epop package.
Decodes multipart content, quoted-printables, base64 and encoded-words.

Before you start

• This program reads from a POP3 mail server, which means that it can only download mail from the inbox folder. If you want to access other folders you will need an IMAP client.
• Handling big attachments requires some processing memory. Normally the program needs about 30Mb RAM, but to process an email with attachments it temporary needs 3 till 4 times of the total size of the email attachments as additional memory.
• Elixir programmers can replace the default Pop3mail.Base64Decoder with their own.
• On linux when there is not enough memory, the program will end as 'Killed.' It's killed by the OOM Killer. Run dmesg to see the log message.
• On windows when there is not enough memory the program get stuck, or worse windows get stuck.
• Do NOT run the script as root.
• Downloaded attachments can contain viruses, addware or malicious scripts.
• This program does NOT convert charsets and neither does it add a BOM. If a message is send in ISO-8859-1, CP1251, KOI8-R it wil be stored as such. Sometimes you must change the locale/charset/encoding (LC_CTYPE luit, chcp) in your terminal/device/program to be able to read the content. Elixir programmers can use codepagex to perform conversions to utf-8.

Gmail users:

• Whether the read mail is permanently deleted or not, depends on your Gmail settings, and not on the delete parameter of this program.
• Gmail returns chunks of maximum 250-350 emails. Repeatedly run this program to get all emails.

Installation from scratch

Install Elixir

Follow the instructions on http://elixir-lang.org/install.html

Also install git and optionally also rebar3.

Clone project

$ git clone https://github.com/nico-amsterdam/pop3mail.git

Compile & unit test

$ cd pop3mail
$ mix deps.get
$ mix test

For usage, see usage chapter below.

Install in an Elixir project

1. Add pop3mail and the erlang epop client to your list of dependencies in mix.exs:

   def deps do

    [{:pop3mail, "~> 1.2"}, 
     {:erlpop, github: "nico-amsterdam/erlpop"}]

   end

Upgrade instructions 1.1.0 to 1.2.0

Version 1.2.0 of Pop3mail consumes far less memory as 1.1.0 when handling big attachments. Erlpop now has additional functions epop_client.bin_retrieve and epop_message.bin_parse. Erlpop is backwards compatible.

Pop3mail requires the latest Erlpop. Run these commands to upgrade:

$ mix deps.update  erlpop
$ mix deps.compile erlpop

Pop3mail biggest changes:

• The function decode_body_char_list is replaced with decode_body_content.
• Pop3mail functions which previously used character list parameters, now use strings.
• Base64Decoder.decodes_lines! is replaced with Base64Decode.decode! It decodes the encoded text and ignores carriage returns and linefeeds.

Usage

Commandline script

The script downloads email and writes the content in the inbox folder.

$ pop3mail_downloader --help
$ pop3mail_downloader --username=<your email username> --password=<your email password> --max=10 --raw

or without shell/batch script:

*nix

$ mix run -e 'Pop3mail.CLI.main(["--help"])'
$ mix run -e 'Pop3mail.CLI.main(["--username=<your email username>", "--password=<your email password>", "--max=10", "--raw"])'

Windows

C:\pop3mail\mix run -e "Pop3mail.CLI.main([""--help""])"
C:\pop3mail\mix run -e "Pop3mail.CLI.main([""--username=<your email username>"", ""--password=<your email password>"", ""--max=10"", ""--raw""])"

The script defaults to Gmail, but you can specify other POP3 server and port settings.

Use in Elixir

Documentation is available online

Example:

$ iex -S mix

# notice that you must use single quotes here
iex(1)> {:ok, client} = :epop_client.connect('user@gmail.com', 'password', 
...(1)>   [:ssl, {:addr, 'pop.gmail.com'}, {:port, 995}, {:user, 'user@gmail.com'}])
iex(2)> :epop_client.stat(client) 
iex(3)> {:ok, mail_content} = :epop_client.bin_retrieve(client, 1) 
iex(4)> {:message, header_list, body_content } = :epop_message.bin_parse(mail_content)
iex(5)> Pop3mail.header_lookup(header_list, "Subject")
iex(6)> Pop3mail.header_lookup(header_list, "From")
iex(7)> Pop3mail.header_lookup(header_list, "Date")
iex(8)> part_list = Pop3mail.decode_body_content(header_list, body_content)
iex(9)> length(part_list)
iex(10)> part = Enum.at(part_list, 0)
iex(11)> part.media_type
iex(12)> part.filename
iex(13)> part.charset
iex(14)> part.content
iex(15)> :epop_client.delete(client, 1)
iex(16)> {:ok, mail_content} = :epop_client.bin_retrieve(client, 2) 
iex(17)> {:message, header_list, body_content } = :epop_message.bin_parse(mail_content)
iex(18)> Pop3mail.header_lookup(header_list, "Subject")
iex(19)> :epop_client.quit(client)

Spam folder

You better turn off the spam folder of your email account if you don't want to miss any email with this program. In Gmail you cannot turn it off, but you can create a filter for spam with the option 'Never send it to spam'.

Reset Gmail

Gmail remembers which mails are already read. Fortunetely Gmail can be reset to re-read all emails.

Login in www.gmail.com. In Gmail webmail Settings > Forwarding and POP/IMAP, select another option for POP, like Download mail from now on. Save change. Go back to settings and select Download all mail, Save change.

Now your email client should download all mail again.

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License

MIT

Acknowledgment

Thanks Erik Søe Sørensen for upgrading the Epop client to the latest Erlang version.