This might be a 'lateral' idea - but why not add a view to your template which has two fields displayed and one 'support' field.
The first field should hold your 'xml snippet' (just set in code the way you currently save to file' and the second a file attachment field.
Now have a button which sends the form by email - and put a rule before the submit which sets the 'support' field to 'true'.
Have an Open rule on your template which when 'support' field is true - switch to XML snippet and attachment view.
Now you can send your required information and attachment using the form itself - via a built in Infopath submit.
(don't forget to set the 'support' field back to false so the original form behaves properly).