A subscriber just said that they were receiving 80 or more copies of my message. How do I make mail-list.com stop sending so many?
First of all, mail-list.com did not send 80 copies of your message to the subscriber. At least it never has in the past. And you will hear from LOTS of subscribers if and when we do have problems.
However, various ISP's have email troubles on a regular basis. They run out of disk space, or have other operational problems that cause the email to be placed in your subscribers mailbox many times.
This problem typically revolves around their ISP's disk being close to full, or their personal mailbox being close to it's size quota. So when your message is delivered to their inbox, an error is triggered, even though the message was successfully delivered. Especially on larger messages. That means the subscriber may receive small messages, but your larger message goes over the quota.
We have also seen duplicates caused by the mail filtering rules in your subscribers email reader. Should they have several rules that all apply to your message, some email readers will create a duplicate copy for each additional rule.
Please do a querysent command (described in the Advanced Owner's Manual) on that subscriber. It will show the audit trail of our machine delivering the message. Assuming that it only shows one message sent to your subscriber, then forward that log entry to your subscriber, and ask them to consult with their ISP.