Using AppleScript to mail merge with attachments

Here is some code that is useful for sending batch emails with Mac Mail to recipients using information stored in a text file. This also enables attaching specific files to the message, again based on the information in the text file.

set mol_list to {}
-- This will ask you to select a file containing the intended recepients and their emails --
-- I also include in this file information needed to link to an attachment --
set theFile to choose file with prompt "Select a text file:"
set theFileReference to open for access theFile
-- Note that the line end here is an old Mac return (not MSFT carriage return) --
set theFileContents to read theFileReference using delimiter return
close access theFileReference

-- Now parse the file that was selected. Here I'm parsing a tab-delimited file. --
set text item delimiters to tab
-- Loop through the file one line at a time --
repeat with i from 1 to count of theFileContents
    set theLine to text items of item i of theFileContents
    copy theLine to the end of mol_list
    -- this identifies each column in the tab-delimited file --
    set stid to item 1 of theLine
    set first_name to item 2 of theLine
    set last_name to item 3 of theLine
    set email_add to item 4 of theLine
    -- specify the location of the file to attach --
    -- here I'm pasting together information from the tab-delimited file to point to the file for this particular recipient --
    set file_attach to "Macintosh HD:Users:USERID:file_" & stid & ".pdf"
    -- Set the message, again pasting together info from the recipient file --
    set message_content to "Dear " & first_name & ",
    This is my email to you containing your information.
    -- Now push this to Mac's mail software
    tell application "Mail"
        -- Create a new message with the message above and the subject --
        set theMessage to make new outgoing message with properties {visible:true, subject:"Set the subject here", content:message_content}
        -- Set the address for this recipient --
        tell theMessage
            make new to recipient at end of to recipients with properties {address:email_add}
        end tell
        -- Add the attachment to this recipient --
        tell content of theMessage
            make new attachment with properties {file name:file_attach as alias} at after last paragraph
        end tell
        -- Add a little delay to attach larger files to the email before sending --
        delay 2
        -- Send the message to this recipient --
        send theMessage
    end tell
end repeat