Send one and not multiple emails with bash script

Send one and not multiple emails with bash script

I have taken over a script from someone, and the bash script works
generally well, but it's not completely polished. So, generally and
simplistically speaking, it sends an email report to people, which it
takes from a text file. So, the problem is this. Each line in that text
file represents the data that should be sent to a user via email. The
script formats the data, so it's easy to read, and sends the email. When
the email is sent, it will have 3 lines in the email for user 1 and 2
lines in the email for user2. Fine good, works well. However, instead of
sending one email each to user 1 and user 2, it sends 3 of the same emails
to user 1 and 2 of the same email to user 2. Essentially duplicates the
email. I guess it's not a huge problem if they only get 2 emails, however,
what if they have 20-30 lines? They can receive 20-30 of the same emails.
Line1: User 1 UnitCost Total Cost RemainingBalance
Line2: User 1 UnitCost Total Cost RemainingBalance
Line3: User 1 UnitCost Total Cost RemainingBalance
Line4: User 2 UnitCost Total Cost RemainingBalance
Line5: User 2 UnitCost Total Cost RemainingBalance
So, what I like to know is, here's the line to send out the email:
printf "$USER\n$MESSAGE\n\n$DETAIL" | mailx -r admin@email.com -s
"Email for balance" "$EMAIL"
So, is there a way without re-writing the script to have mailx send out
one email per recipient? Not sure what's the best method here. Any input
would be appreciated!