The EFT Outlook Add-In uses Outlook's proofing language detection to determine in which language an email is written. If you want to enable the Auto detect email language setting, you must enable Outlook's Detect language automatically proofing setting.
Before Outlook's Detect language automatically option can detect the language that you are typing and enable the proofing tools for that language, you must turn on the language-specific options you want to use.
To turn on language specific options
For Microsoft Office 2007, refer to the Microsoft Office article at http://office.microsoft.com/en-us/outlook-help/enable-the-use-of-other-languages-in-your-office-programs-HA010243503.aspx.
For Microsoft Office 2010 and later, refer to the Microsoft Office article at http://office.microsoft.com/en-us/outlook-help/enable-the-use-of-other-languages-in-your-office-programs-HA010354783.aspx.
To enable Outlook's Detect language automatically proofing setting
For Outlook 2007, refer to the Microsoft Office article at http://office.microsoft.com/en-us/outlook-help/turn-on-automatic-language-options-HA010244823.aspx.
For Outlook 2010 and later, refer to the Microsoft Office article at http://office.microsoft.com/en-us/outlook-help/turn-on-automatic-language-options-HA010354274.aspx.
From the Microsoft Office links above: "Automatic language detection does not work on a single-word basis, but on a sentence basis. Depending on the length of your sentences, you might need to type several sentences before Outlook has enough contextual information to automatically detect the language and apply the correct dictionary."
Outlook must be restarted for the changes to take effect. After you have turned on the language-specific options in Microsoft Office and enabled Outlook's Detect language automatically proofing setting, then the Add-In's automatic language detection feature will be enabled.