So that your customers will receive the email they have requested.
mail-list.com runs confirmed opt-in mailing lists. That means each subscriber on our lists has confirmed their intent to be on our lists, from their own email address. And our system stores this response.
Therefore, mail-list.com should not be on any spam filters, and all ISP's should accept our email.
We operate several networks, and guarantee that no spam is sent nor relayed from any of our machines.
If you have any clues to the contrary, please send the email headers to us.
Please add the following IP Addresses to your list of good guys, so that the emails your customers have asked for, will be delivered.
Here's the same list of IP Addresses, in a format that should be easier to copy and paste.
All of these machines have valid DNS PTR records, from our upstream provider - Amazon.
Thank you for your help in ensuring the smooth delivery of our confirmed opt-in emails to your customers.