[Mailman-Users] Automatic messages still going out from defunct list

[mph28 at hotmail.com]

Hello I wonder if you can help me. We are a residents' association and we had been using mailman to contact our members. We then had to change our hosting and the mailman option was suddenly and unexpectedly no longer available. We 'lost' our mailing list in that it was no longer possible to access it and administer it. We are now going to use a different system for our email contact with members but unfortunately everybody is still receiving the monthly reminders. How can we stop those from being sent out and close down the list properly?