It is possible to import an HTML file into a Lotus Notes, if the it has rich-text field. To find out whether or not it is to import to is a rich-text field, any rich-text field is listed as Data Type !
To import HTML file
1. File > Import. (this option is not available if the field that r selected is not a rich-text field)
2. On Import dialog box, select HTML File in the Files of type list
3. Now select the drive and directory (where is the files located)
4. Click Import
Hope it works !