To make sure Outlook always sends emails in plain text to certain addresses:
Go to Outlook’s navigation pane and select People or Contacts (depending on the version of Outlook you use), or press Ctrl+3. In Outlook 2007, select Go > Contacts. Go to Home > Current View > Card or Business Card. Locate and double-click the desired contact. Select the Email dropdown arrow and choose the email address you want to set to plain text. In the upper-right corner, double-click the email address that should receive plain text messages. In the Email Properties dialog box, select the Internet format dropdown arrow and choose Send Plain Text only. If the Edit Business Card dialog box opens, see below for how to change the Windows Registry to access the Email Properties dialog box. Select OK. Close the contact window.
Force the Email Properties Dialog for Addresses in Outlook 2016 and Outlook 2013
To have Outlook always show the Email Properties dialog when you double-click a contact’s email address:
Close Outlook. In Windows, press Windows+R. In the Run dialog box, type regedit. Select OK. If prompted by User Account Control, select Yes to allow this app to make changes. For Outlook 2016, go to: HKEY_CURRENT_USER\Software\Microsoft\Office\16. 0\Common\Contactcard For Outlook 2013, go to: HKEY_CURRENT_USER\Software\Microsoft\Office\15. 0\Common\Contactcard If the Contactcard key exists in the registry, go to step 12. If you do not see the Outlook version key in the registry, you’ll need to create a new key. For Outlook 2016, go to: HKEY_CURRENT_USER\Software\Microsoft\Office\16. 0\Common For Outlook 2013, go to: HKEY_CURRENT_USER\Software\Microsoft\Office\15. 0\Common Go to Edit and select New > Key. Type Contactcard and press Enter. Go to Edit and select New > DWORD (32-bit) Value. In the Name column, type turnonlegacygaldialog and press Enter. Double-click the turnonlegacygaldialog value. In the Value data text box, enter 1. Select OK. Close the Registry Editor. You can now follow the instructions to set the sender to receive plain text emails.
For Outlook 2013, go to:
For Outlook 2016, go to:
For Outlook 2013, go to:
