The abbreviation MIME stands for Multipurpose Internet Mail Extensions and refers to a media or content type on the internet. With MIME, the data contained in an internet message can be clearly classified as it would in an email or in a HTTP message. The MIME information informs which type of data the mail server or email sender has sent. These may be texts, pictures, videos or other formats. Within the email traffic, a separate header field is provided for this type of information. It is called Content-Type.
MIME information is made up of two parts: the media type and the subtype - the MIME syntax separates the media type and subtype with a slash, and MIME information is displayed as ‘image / png’ in cases where the transmitted information is a picture file in the PNG format (Portable Network Graphics).
There are over 100 different types of MIME media subtypes. The media types are managed by the Internet Assigned Numbers Authority. If the MIME information is missing in a message, the recipient can determine the type of media using a process called MIME sniffing. This method analyses the first or last bytes of a document. The format is derivable from the read information for many file types. MIME sniffing should only be used if the MIME type is missing.
In the case of internet faxing services, fax documents can be transmitted as an attachment to an email. T.37, exists for this purpose and ensures that the fax document to be transmitted is converted to a file (often in TIFF format) and transferred via SMTP (Simple Mail Transfer Protocol). Within the email, T.37 uses the MIME format to generate information about the media type. With T.37 and a fax gateway, faxes can be sent by email from any terminal to a conventional fax machine connected to a telephone line. The fax gateway converts conventional faxes into e-mails and vice versa.
The online fax offers numerous advantages. Users need neither a fax machine nor a telephone connection, and can send and receive online faxes directly from the email application of their PC, laptop, smartphone or tablet device without any specific software. The management of faxes has become a lot more convenient and streamlined since the invention of the internet fax, due to the fact that faxes can now be stored and organised just like emails, without the need for paper documents.