catchall

catchall is a simple all-in-one mail server for catching all email and funnelling it to a single catchall address which is available for pickup.

Overview

Use as your own personal "mailinator" or simply because you want tons of throw-away email addresses when throw-away domains are not permitted.

This is not another SquirrelMail or Roundcube replacement. I wanted minimal setup and container portability for a single user to receive email at multiple throw-away addresses for throw-away services.

Features

• All-in-One SMTP server (receiving) and POP3/IMAP server (retrieving)
• Docker Secrets compatibility
• Provides TLS services by leveraging Let's Encrypt as a sidecar
• Automagic restart when new certificates are found

Not Supported (Yet)

• HTTP UI / API

My first goal was to get emails available for pickup and import by other services (Gmail, specifically). Providing a web-based UI or API means additional processes (which there already are a lot), and databases to keep consistent with the mail spool on disk.

• Sending email

This was just designed as a "mailinator"-clone, so I have not implemented sending emails.

Environment Variables

ALIASES

Space-separated list of alias domains to also receive mail.

ALIASES="contoso.home fabrikam.com"

CATCHALL

The name of your catchall account. All emails (not sent to /dev/null) will be aggregated and forwarded to this account.

# default
CATCHALL=catchall

DEVNULL

Space-separated list of email addresses to send to /dev/null.

DEVNULL="[email protected] [email protected]"

DOMAIN

Primary domain to accept email.

DOMAIN="contoso.com"

HOSTNAME

Hostname to present. This MUST match the Common Name on your SSL certificate.

HOSTNAME="mail.contoso.com"

PASSWORD (or PASSWORD_FILE)

Set the password for your catchall account.

If you do not specify a password (or password_file), the container will automatically generate a very complex and secure one for you and print to the console.

PASSWORD="hunter2"
# or
PASSWORD_FILE="/run/secrets/catchall-password"

SLACK_URL_FILE

When certbot successfully renews a certificate, you can be sent a slack notification as confirmation.

SLACK_URL_FILE="https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX

STARTUP_DELAY

Number of 2-second iterations to wait for certificates before failing startup.

# default
STARTUP_DELAY=5

TIMEZONE

tz-compatable timezone for log files and timestamping. Please see the list of tz database time zones.

# default
TIMEZONE="Etc/UTC"