EML file format denotes a single email message that has been stored in a file. This file follows the regulations of RFC 822 standards. EML file extension is very much equipped in supporting the ASCII text format for the email headers. In addition to this, the rest of the email body can also store email attachments and hyperlinks. EML files, in particular, are supported by Microsoft Outlook Express. But in addition to that, there is a huge list of email clients that support EML files.