FTH - Treasurer funtion - Dues

In FTH, under treasurer function - dues management there is a section where it says:
You can also send follow-up emails to unpaid/paid members using one of the following methods. The recipients will correspond to what is selected on the Send Notices/Track Payments tab.
duesnotpaid-4630@toastmastersclubs.org
duespaid-4630@toastmastersclubs.org
NOTE: The above email list addresses are not published in your club email addresses listing, due to the sometimes sensitive nature of collecting dues. However, any officer can send emails to these email addresses from their email software after the selections on the Send Notices/Track Payments tab have been saved.

When I click on "Basic follow-up -Email dues paid", it allows me to compose and email and shows the list of people who have been selected in the "To" tab.
I write the "Email Subject" and then "Email body" and then click on "Send email" .
It shows "Email sent".

But the problem is none of the recipients have received the email. I have tried this several times and it does not seem to work.
What could be the problem?

"The recipients will correspond to what is selected on the Send Notices/Track Payments tab."

Did you actually select any recipients? I tested this on our test website and everything looks fine to me.

That is a different option/tab. I have successfully used the notice/invoice option.

The tab I am talking about is "Dues follow up"

Treasurer Function Dues--> in dues management choose the 4th tab "Dues follow up" ---> click on "Basic-Follow-up Email-PAID DUES"--> Recipients are already mentioned according to the "Send notices/Track payments" tab --> compose email --> click on "Send Email" ---> It says "Email sent"

But no member, including myself, ever receives that email.

Please test this option on your test website.
Thank you

I can see 3 people have not paid their dues and when I click the follow-up email for unpaid
Ahmad, Kim, Regina

SUCCESS (Form Email) Sat 2018/09/22 16:30:07 UTC Club:[4630] From:["Admin via Toastmasters Club 4630" <server@toastmastersclubs.org>] To:[ahmadmaq@gmail.com] CC:[] Subject:[Your dues remain unpaid]
SUCCESS (Form Email) Sat 2018/09/22 16:30:07 UTC Club:[4630] From:["Admin via Toastmasters Club 4630" <server@toastmastersclubs.org>] To:[klagle@mail.com] CC:[] Subject:[Your dues remain unpaid]
SUCCESS (Form Email) Sat 2018/09/22 16:30:07 UTC Club:[4630] From:["Admin via Toastmasters Club 4630" <server@toastmastersclubs.org>] To:[lyssi80@yahoo.comrvaldez@fswf.org, rvaldez@fswf.org] CC:[] Subject:[Your dues remain unpaid]

Correct! Does this show that email has been sent successfully?

I tested this and added myself to not paid dues list - but did not receive any email.
But I receive the invoice email. So can not be a server issue?

Yes it shows the emails were send to the 3 selected non-paid members.

You have to select SEND to everyone you want emails sent to, you only have the NON paid members selected.