m2m - Move from POP3 to Maildir

• v1.25.2
• License: GPLv3+
• Just pull mails from POP3 servers (TLS can be disabled) and put them in local Maildirs.
• Proxies and Onion entry servers are supported.
• Multiple accounts supported, which are accessed concurrently.
• RFC6856 compliant (UTF8 before anything) so works with Courier as well.
• It can keep mails on the server, but does not remember/store which mails have been seen.
• Expanded from github.com/unkaktus/mm

Install

# Download (replace BINARY by: m2m, m2m_pi, m2m_osx, m2m_freebsd or m2m.exe)
wget -O BINARY https://gitlab.com/pepa65/m2m/-/jobs/artifacts/master/raw/BINARY?job=building

# Go install (if Golang is installed properly)
go install github.com/pepa65/m2m@latest

# Go clone/install (if Golang is installed properly)
git clone https://github.com/pepa65/m2m; cd m2m; go install

# Smaller binaries
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-s -w"
CGO_ENABLED=0 GOOS=linux GOARCH=arm go build -ldflags="-s -w" -o m2m_pi
CGO_ENABLED=0 GOOS=freebsd GOARCH=amd64 go build -ldflags="-s -w" -o m2m_freebsd
CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -ldflags="-s -w" -o m2m_osx
CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -ldflags="-s -w" -o m2m.exe

# More extreme shrinking:
upx --best --lzma m2m*

# Move them to the local binary directory (if in your PATH):
mv m2m* ~/bin/

# Or move to a manually managed binaries location:
sudo mv m2m* /usr/local/bin/

Configuration

• The directory ~/.m2m.conf contains all the account config files which are checked concurrently. The file name is taken as the account name, must not start with a .! (See the Example file in the repo).
• The (YAML) config files have the POP3 server config details and the Maildir location with parameters:
  • active: true/false - Account is active [default] or not
  • username: POP3 username [mandatory]
  • password: POP3 password [mandatory]
  • tlsdomain: Server domainname (as in its certificate) [mandatory]
  • port: Port [default: 995]
  • entryserver: Initial IP/Domainname for the server [default: not used]
  • proxyport: Proxy server (server:port) [default: empty, not used]
  • tls: true/false - Use TLS [default] or not
  • timeout: Poll timeout in seconds [default: 200]
  • keep: true/false - Keep mails on the POP3 server, or delete them [default]
  • maildir: Path to Maildir [default: ~/Maildir]
  • Default options are taken when the parameter is not specified.
  • Comments are lines starting with '#'.

Run

• Usage: m2m [-s|--serial] [-q|--quiet] | [-h|--help]
• Normally, a minimal report is sent to stdout (nothing on no mails), and any additional verbose output is logged to stderr. Route this output as desired!
• Flag -q/--quiet outputs only fatal errors to stderr.
• Flag -h/--help outputs just a help text.
• While running, each account gets locked with LOCK_EX Flock on the account file ~/.m2m.conf/ACCOUNT when it gets checked online.
• The -s/--serial flag can be used if you want to process in strict lexical order instead of concurrently.

Help

m2m v1.25.2 - Move from POP3 to Maildir
* Downloading emails from POP3 servers and moving them into Maildir folders.
* Repo:   github.com/pepa65/m2m
* Usage:  m2m [-s|--serial] [-q|--quiet] | [-h|--help]
    -s/--serial:   Check the accounts in order, do not check concurrently.
    -q/--quiet:    Output only on critical errors (on 'stderr').
    -h/--help:     Output this help text.
    -V/--version:  Output the version.
    If mails are found, a minimal report goes to 'stdout'; errors to 'stderr'.
* The directory '~/.m2m.conf' contains all account config files, which are
  checked concurrently by default (each filename is taken as the account name).
* Parameter names (lowercase!) in the configuration files:
    active: true/false  Account is active [default] or not
    username:           POP3 username [mandatory]
    password:           POP3 password [mandatory]
    tlsdomain:          Server domainname (as in its certificate) [mandatory]
    port:               Port [default: 995]
    entryserver:        Initial server IP/Domainname [default: not used]
    proxyport:          Proxy server (server:port) [default: not used]
    tls: true/false     Use TLS [default], or not
    timeout:            Poll timeout in seconds [default: 200]
    keep: true/false    Keep mails on POP3 server, or delete them [default]
    maildir:            Path to Maildir [default: '~/Maildir']