Even more tweaks to inbound and replies

Three clear paths for custom sending domains, each with consistent, predictable reply behavior.

Justin Duke
Justin Duke
June 24, 2026
Even more tweaks to inbound and replies

We launched a revamped reply tracking back in February, and it's gone over very well in many respects. However, the passage of time has revealed, as it always does, a few warts and errors in our thinking, and we're changing how we do things as a result. Thanks, everyone, for providing your feedback and in some cases your patience. We knew we were being a little prescriptive and heavy-handed with how we rolled this out, and did so largely in order to simplify the setup process — but it's clear that the edge cases were more common than we had anticipated.

First, to lead with the changes themselves:

  1. For manual custom sending domains (i.e., you are not delegating a subdomain to us), we will never set an MX record on your behalf. You must provide your own.
  2. Additionally, on manual custom sending domains, reply tracking now defaults to off — replies flow straight to your own inbox — though you can turn it back on yourself any time under Settings → Sending domain → Add-ons.
  3. If you're using a managed custom domain (i.e., delegating the sending domain to us), the reply-to address — which has been hitherto hidden, requiring you to write to support to enable it — is now generally available under the Domain Settings page.

Here's a table walking through the three paths as a result:

Shared domainManaged custom domainManual custom domain
MX recordMX record is irrelevantWe set an MX record for you.We never set an MX record, and you must provide your own.*
Reply trackingYou cannot opt out of reply tracking.You cannot opt out of reply tracking.Off by default; flip it on (or off) under Add-ons.*
Reply-toYou cannot set a custom reply-to.You can set a custom reply-to, and this is generally available.*A custom reply-to is irrelevant, because you're providing the email address of your choosing.

Hopefully this clarifies the three options you have when setting up your newsletter a bit:

  1. You can use our shared domain, which requires no setup but also begets little customization;
  2. Use a custom domain in managed mode, which makes it easy to send from your own domain though limits your customization slightly;
  3. Or use a completely manual custom domain, which affords you ultimate flexibility, but now you have to deal with DNS records.

None of these changes require any work on your part. If you've already set up a custom domain, then it will continue working just fine as is.

* These defaults apply to manual domains set up from here on out. If you're already on a manual setup, your replies keep working exactly as they do today — and whichever way you'd prefer, reply tracking is now a self-serve toggle under Settings → Sending domain → Add-ons, so you can take over your own replies (or hand them back to us) without writing in.

Buttondown is the last email platform you’ll switch to.