Recently I stopped receiving Delivery Status Notifications even though I have that checked on every email I send. I have read that some servers will not respond to DSN but I am sending to the same email addresses I had always received DSNs from until about 2 weeks ago. I have tried disabling add on's with no luck. I am using Thunderbird version 86.0b3. I do still receive Read Receipts when I request them & when they are responded to by the recipients. Below is what the notification contents looked like. Any advise to correct this would be greatly appreciated. from: [email protected] This is the mail system at host proxyz13.mailnet.ptd.net. Your message was successfully delivered to the destination(s) listed below. If the message was delivered to mailbox you will receive no further notifications. Otherwise you may still receive notifications of mail delivery errors from other systems.