Replies come back on your domain now - and nothing invites a reply that bounces

This started with a bounce. A reply to a test email came back rejected - “554 … Downstream server error” - because the address it was sent from was send-only. There was no mailbox behind it and no Reply-To pointing anywhere else, so the reply went to an address that cannot receive mail. The recipient thinks they answered you. You never hear from them. Two things changed. First, every email the product sends now carries a Reply-To that reaches a real destination - meeting invites and reminders, survey requests, subscription confirmations, support acknowledgements, and every test send. One-to-one mail and campaigns already did this; nothing else did, and each of those was one reply away from the same silent failure. There is one deliberate exception: if an address is one a person actually reads, it is left alone. Quietly diverting someone’s mail into the CRM because we could would be its own bug. Second, and optional: replies can now arrive on your own domain. Publish one MX record and replies go to reply.yourdomain.com instead of a shared address on ours. Why bother, when the shared address worked? Because a Reply-To on a domain unrelated to the one you send from is exactly the shape phishing takes, and filters and people both notice. To be precise about it: Reply-To is not part of SPF, DKIM or DMARC and cannot fail authentication - anyone telling you otherwise is wrong. It is a trust signal, not an auth check. But it is a real one, and it was the last piece of your email still wearing our name. It also made the address shorter, which sounds cosmetic and isn’t: on the shared domain the workspace has to be identified by a 52-character token in the address itself, which pushes past the length limit the standard sets once anything is added to it. On your own domain the domain identifies you, so the address is simply reply@reply.yourdomain.com - and it carries your brand name in front of it rather than arriving as a bare machine-generated string. Turning it off is safe. Replies fall back to the shared address, which has always worked and still does. Nothing bounces, nothing is lost, and the reply still threads onto the right record either way.