We have found one software suitable in our database for this conversion.
Some email clients allow users to export email messages (.eml) as JPEG pictures (.jpg, .jpeg), which can also be achieved using several online conversion services like ZAMZAR. The result of eml to jpg conversion or export will be a simple bitmap image that contains the text from the email in it.
If the picture is just an attachment to the message, you have to just to save it as separate file, no need to convert eml to jpg.
EML
An eml file extension is used by various e-mail clients, such as Microsoft Outlook, Windows' default mail client, Thunderbird, etc. An eml file contains saved email messages either meant as backup or for sharing.
JPG
Files with jpg file extension contain pictures, digital photos, and other bitmap images. It is one of the most common image formats used today.