# reply.py, a simple python autoresponder

This program is inteded for use with postfix, or any other MTA that can 
forward emails to a program for processing.

## How it works

The program reads a complete email from stdin and responds to it, 
maintaining threading information.

The program looks for autoresponses in the `templates` subdirectory.

If the local part of the recipient address matches the name of a template in 
that directory, that template is sent in a reply to the sender.

If there is no match, the template `default` is used. If no default template 
exists, a failed match will cause an error.

The automatic choice of template can be overridden by specifying a template 
on the commandline. If the specified template doesn't exist, the program will 
throw an error.

### HTML responses

Optionally, alternative HTML versions of templates may be provided.

In order to use an HTML template, add your HTML content to a template file 
with the `.html` suffix. There *must* also be a template file for plaintext 
responses (same filename without the suffix).

For example, if there is a `default.html` template file along with `default`, 
autoresponses using the `default` template will also include an HTML-formatted 
version of the reply. If only `default.html` exists, the program will throw 
an error.

## Example usage

In the postfix aliases file, you can trigger this program by using the 
pipe operator: 

```
someaddress: |"/path/to/reply.py"
anotheraddress: |"/path/to/reply.py sometemplate"
```

In the first case, the program will look for the template `someaddress`. If 
that template doesn't exist, it will fall back to the template `default`.

In the second case, the program will look for the template `sometemplate`. An 
error will be thrown if that template doesn't exist.

In both cases, if the corresponding `.html` file exists, the response will 
include an HTML version of the message as well.

Other MTA:s may have different mechanisms to call external programs.