EmailReader reads a store of email messages, either locally from a delimited flat file, or on an external server.

Component	Same input metadata	Sorted inputs	Inputs	Outputs	Java	CTL	Auto-propagated metadata
EmailReader			1	2	-	-

When looking at ports, it is necessary for use-case scenarios to be understood. This component has the ability to read data from a local source, or an external server. The component decides which case to use based on whether there is an edge connected to the single input port.

Case One: If an edge is attached to the input port, the component assumes that it will be reading data locally. In many cases, this edge will come from a FlatFileReader. In this case, a file can contain multiple email message bodies separated by a chosen delimiter and each message will be passed one by one into the EmailReader for parsing and processing.

Case Two: If an edge is not connected to the input port, the component assumes that messages will be read from an external server. In this case, the user must enter related attributes, such as the server host and protocol parameters, as well as any relevant username and/or password.

Port type	Number	Required	Description	Metadata
Input	0		For inputting email messages from a flat file.	String field
Output	0		The content port	Any
	1		The attachment port	Any

EmailReader does not propagate metadata.

EmailReader has metadata templates on its output ports.

Fields of the templates have to be mapped using the Field Mapping attribute. Otherwise, null values are sent out to output ports.

The number of attributes which are required or not depends solely on the configuration of the component. See Ports: in Case Two, where the edge is not connected to the input port, more attributes are required in order to connect to the external server. At minimum, the user must choose a protocol and enter a hostname for the server. Usually, a username and password is also required.

EmailReader is a component suitable for reading of online or local email messages.

This component parses email messages and writes their attributes out to two attached output ports. The first port, the content port, outputs relevant information about the email and body. The second port, the attachment port, writes information relevant to any attachments that the email contains.

The content port will write one record per email message. The attachment port can write multiple records per email message; one record for each attachment it encounters.

Mapping Fields

If you edit the Field Mapping attribute, you will get Email to Clover Mapping dialog:

Figure 54.12. Mapping to Clover fields in EmailReader

In its two tabs - Message and Attachments - you map incoming email fields to Clover fields by dragging and dropping. You will see metadata fields in a particular tab only if a corresponding edge is connected and has metadata assigned. The first output port influences the Message tab, the second output port influences the Attachments tab.

Buttons on the right hand side allow you to perform Auto mapping, Clear selected mapping or Cancel all mappings. Buttons on the left hand side add or remove user-defined fields.

User-defined Fields

User-defined Fields let you handle non-standardized email headers. Manually define a list of email header fields that should be populated from email message. For example, you can read additional email headers like Accept-Language, DKIM-Signature, Importance, In-Reply-To, Received, References, etc.

See details on message headers at http://www.iana.org/assignments/message-headers/message-headers.xhtml.