smtp2http

SMTP to HTTP gateway

Usage

Usage: smtp2http [-v|--verbose] [-s|--silent|-q|--quiet]
    [-T|--tls=<tls_opt>] [[-H|--header=<header>], ...] ENDPOINT

 -H --header=<header>   HTTP header to send with requests
 -q --quiet             Do not log to STDERR
 -s --silent            Alias for --quiet
 -T --tls=<tls_opt>     colon-delimited list of cert files
                        q.v. TLS Option below
 -v --verbose           Log information to STDOUT

TLS Option
The --tls option accepts a colon-delimited list of certificate files.
You can specify a single combined PFX file, a cert file followed by a
key file, or a cert file followed by a key file followed by a signing
authority certificate.

Examples

Begin listening for incoming SMTP messages, parse them, and post them to the specified HTTP endpoint.

smtp2http https://example.com/foo

TLS Support

Enable TLS using separate certificate and key files with signing CA cert.

CERT=/etc/private/ssl/example.com.crt
KEY=/etc/private/ssl/example.com.key
CA=/etc/private/ssl/example.com-ca.crt
smtp2http -T$CERT:$KEY:$CA https://example.com/foo

Enable TLS using cert and key files only.

CERT=/etc/private/ssl/example.com.crt
KEY=/etc/private/ssh/example.com.key
smtp2http -T$CERT:$KEY https://example.com/foo

Enable TLS using single PFX combined cert file.

CERT=/etc/private/ssl/example.com.pfx
smtp2http -T$CERT https://example.com/foo

Install

git clone [email protected]:Zingle/smtp2http.git
cd smtp2http
npm install -g

Development

The SMTP protocol does not provide any way to set the TCP port used for communication. Because of this, development can be difficult if trying to use public mail providers because you must have an internet facing server listening on port 25.

You can run something like the following to set up a reverse tunnel using a public server to which you have SSH access.

ssh -fNR 25:localhost:2025 [email protected]
SMTP_PORT=2025 smtp2http

In this example, example.com is the public server to which you have access, root is a user with access to open low-numbered ports on that host, 25 is the port this host will listen on (standard SMTP port), and 2025 is the port smtp2http will listen on.

Appendix - Generating a PFX cert

If you have a typical PEM cert with separate key and cert files, you may wish to generate a PFX cert which is simple to specify.

openssl pkcs12 -export \
    -out example.com.pfx \
    -in example.com.crt -inkey example.com.key \
    -certfile example.com-ca.crt