sumizadocker/smtp-parser repository overview

⁠SMTP Server Parser

The SMTP Server Parser is a python based smtp server that can be used to check incoming emails for various properties, such as SPF and DKIM verification, before accepting them. It can also send the email to a webhook, or print it to the console, depending on the configuration.

There are advance options as well with addon scripts that can do custom parsing or sending.

https://github.com/Sumiza/smtp-parser⁠

https://hub.docker.com/r/sumizadocker/smtp-parser⁠

⁠Docker Hub Tags

To keep the dependencies up to date a new build is made daily and tagged as latest, if you want to lock into a specific build use the date or commit hash. Or use the master tag to only update when there is a change to the code.

• latest : Updated daily and when a new build is done
• master : Updated when a new build is done
• date : Daily build
• commit hash : Github commit build
• beta : Beta changes from the beta branch, might be broken. Dont use.

⁠Environment Variables

The following environment variables can be set to configure the SMTP server:

• HOST: The IP address or hostname to bind the SMTP server to. Defaults to 0.0.0.0.
• HOST_NAME: The hostname for the SMTP server if it can not be set by host because of nat or running a docker container not on the host network.
• PORT: The port number to bind the SMTP server to. Defaults to 25.
• TARGET_EMAIL: An optional email address to filter incoming emails by. If set, the SMTP server will only accept emails that are addressed to these email addresses. It uses .endswith and accepts a list seperated by "," '.com, @example.com, [email protected]' or a single email '[email protected]'
• SOURCE_EMAIL: An optional email address to filter incoming emails by. If set, the SMTP server will only accept emails that are sent from this email address. It uses .endswith and accepts a list seperated by "," '.com, @example.com, [email protected]' or a single email '[email protected]'
• SPF_ALLOW_LIST: An optional string containing a list of allowed SPF responses 'pass, permerror, fail, temperror, softfail, none, neutral'.
• DKIM_REJECT: An optional boolean value indicating whether to reject emails that fail DKIM verification. If set to anything, any email that fails DKIM verification will be rejected. If not set, emails will not be rejected based on DKIM verification.
• DKIM_MIN_KEY: Minimum allowed key size for DKIM verification only need to change if working with legacy systems. default is 1024
• IDENT: An optional string that will be used as the identity string for the SMTP server. Defaults to an empty string.
• EMAIL_SIZE: An optional integer value indicating the maximum size of an incoming email, in bytes. Defaults to 5048576.
• LOGGER: An optinal string accepting DEBUG,INFO,OFF will print out info about incoming emails, default is INFO.
• WEBHOOK_URL: An optional string containing the URL of a webhook to send incoming emails to. If set, the SMTP server will send incoming emails to this webhook.
• WEBHOOK_HEADERS: An optional JSON-formatted string containing a dictionary of headers to include in the webhook request. If set, the headers in this dictionary will be added to the webhook request.'{"Test-Header":"Hi There","Test-Header2":"4"}'
• HMAC_SECRET: An optional string containing a secret key to use for HMAC validation of the webhook request. If set, the webhook request will include an HMAC signature for validation.
• PIP_INSTALL: An optional string containing any projects you need to download with pip for addon scripts 'webhookbin urlrequest secondstotext'
• BUILTIN_ADDON: An optional string containing any of the built in addons
• TLS_CERT_HOST: An optional string that will generate a self signed certificate with the hostname provided.
• TLS_REQUIRED: An optional string that sets if TLS is required to receive emails, needs a premade certificate to be added or generate a self signed one with TLS_CERT_HOST.
• DOWNLOAD_ADDON: An optional url of a addon.py file that will be downloaded with wget.

⁠Usage

To use the smtp server, simply run the Python script or docker container. The SMTP server will bind to the specified host and port and begin accepting incoming emails.

Incoming emails will be checked for SPF and DKIM verification, and filtered according to the configuration specified in the environment variables. If an incoming email passes all checks, it will be sent to the webhook URL specified in the environment variables, or printed to the console, depending on the configuration.

⁠Dependencies

• Python 3.7 or higher
• The spf package
• The requests package
• The aiosmtpd package
• The dkim package

⁠Advance Options

Todo

⁠Custom addon scripts

Todo

⁠Script Examples

Todo