If you delete the Sent To folder you will lose all your Sent to options and probably introduce an issue that would cause File Explorer to malfunction. I wouldn't do that. Also why it is so important to do it with right-click and Sent to? Just create a new email in whatever application you use, click on the Attach button and select multiple files. Holding the SHIFT key selects all the files between the first and the last, holding the CTRL key allows you to select out of order files by clicking on each to mark it. Just like you do it in File Explorer. If you need to select all files with a specific attribute, such as all files created a specific date, just change the view to sort by date and then use the SHIFT button to select them all in order. Probably you can also do it from File Explorer, just select the files you want to attach, but instead of right-click, drag and drop them into the attachment area of your new email message.
PS: Now I saw your screenshot, as mentioned before the "Mapimail" association doesn't work. See post #61 for details.
