I'm using MailChimp, and I sent out a test newsletter to myself, and the title had ADV: added to the beginning of my title. I'm not sure if MailChimp did that on its own, or if it was outlook ...
I'm aware of read receipts in emails, but these mean that the reader has to agree to send back the read receipt. But with Mailchimp (and perhaps others) they have a dashboard to show you which people ...
I have ~20 lists, all of which are mostly announce-only (newsletters--recipients do not reply back to the list) running in GNU Mailman. It's alright. Mailman has certainly prooven itself but we want ...