Technical information

MIME Encapsulated E-Mail Messages
2-62 AT+i Commands Reference Manual May 31, 2008
MIME Encapsulated E-Mail Messages
W24-Generated Binary Message Formats
Binary e-mail messages are sent via W24 using one or more AT+iEMB commands. The message
format is limited to an optional body of text and a single attachment.
The following fields are added by W24 to the main message header:
X-Mailer: iChip <software version>
Message-ID: <Unique #>@iChip
Mime-Version: 1.0
Content-Type: multipart/mixed; boundary="CONE-iChip-<software
version>"
The message's preface contains the following text:
"This MIME message was coded by iChip."
If the host application includes a text body for the message, it also contains the following lines in
its header:
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-iCoverpage: Email
When no textual body contents are included - this section is omitted.
The binary attachment section follows, beginning with a MIME attachment header containing the
following fields:
Content-Type: <User defined media type>/<User defined media
subtype>;
name=<User defined attachment filename>
Content-Transfer-Encoding: base64
where,
• <media type> := "text" / "image" / "audio" / "video" / "application"
• <media subtype> := <A publicly-defined extension token.>
• <filename> := <User-defined name (including extension)> or <unique filename>
• <media type> defaults to "application" when otherwise not defined.
• <media subtype> defaults to "octet-stream" when otherwise not defined.
Following the header, a base 64-encoded data stream includes the entire binary data transferred to
W24 from the host.
MIME-Related AT+i Commands and Parameters
Binary images are transferred to W24 for MIME message encapsulation via one or more
AT+iEMB commands. An AT+iEMB command sequence must be terminated by the AT+iE*
command, indicating the end of the binary e-mail message.