A Multipurpose Internet Mail Extensions (MIME) type in the Content-Type header defines the content type inside a SIP MESSAGE request, e.g., HTML. PortaSIP supports the following MIME types:
- text/plain (default type) – to indicate plain “unformatted” text.
- message/cpim – to indicate the Common Presence and Instant Messaging (CPIM) message format.
- text/html* – to enable using HTML formatting such as bold or underlined text.
- application/im-iscomposing+xml* – to notify a user that the other one is typing a message. The sender is not charged for sending such service messages.
- application/x-acro-filetransfer+json* – to enable users of Acrobits applications to use the multimedia messaging service (mmmsg) that facilitates file transfer among them. Please refer to Acrobits for details.
* Note that this MIME type is supported for SIP-to-SIP (on-net) messages only. If the SMPP protocol is used for message delivery, IMGate rejects SIP MESSAGE requests with this MIME type.
