Inbound vs outbound email
Email-based support involves two completely separate plumbing systems. Inbound is "customers send us mail, we turn it into tickets". Outbound is "we reply, the customer receives it". They have different deliverability rules, different identity requirements, and different failure modes.
Inbound email
Inbound is the easier of the two. A customer sends mail to an address you own, that address routes to message.com, and we create a channel: "ticket" conversation.
There are three ways to expose an inbound address:
| Kind | Address looks like | Setup |
|---|---|---|
auto | <slug>@inbound.message.com | Created automatically on signup. Zero DNS. |
subdomain | support@<slug>.inbound.message.com | Pick a subdomain. Zero DNS. |
custom_domain | [email protected] | Add an MX record. Forward or route directly. |
Inbound delivery is webhook-driven. See email inbound webhook for the payload shape and signature verification.
Outbound email
Outbound is harder because it touches the deliverability gauntlet: SPF, DKIM, DMARC, bounce handling, complaint feedback, suppression lists. message.com uses Resend as the outbound ESP. Replies sent from the agent dashboard go out through Resend and arrive in the customer's inbox.
For outbound email to leave your own domain (rather than <slug>.inbound.message.com), you must add and verify the domain through the email domains endpoint. Verification means publishing the right DKIM and SPF records in DNS.
Deliverability concerns
Outbound has three failure modes you need to handle:
- Hard bounce. The address does not exist. Suppress immediately.
- Soft bounce. Temporary failure (full mailbox, server down). Retry; after three consecutive soft bounces, suppress.
- Complaint. The customer hit the spam button. Suppress immediately. This is the most damaging signal because ISPs use complaint rate to score sender reputation.
message.com maintains a per-workspace suppression list. The platform never sends to addresses on that list. See email outbound webhook for the events that populate it.
Avoiding auto-reply loops
Inbound has its own failure mode: auto-replies. Vacation responders, out-of-office messages, and other automated mail can ricochet into a ticketing loop. message.com drops messages with From: MAILER-DAEMON, Auto-Submitted: auto-replied, and Precedence: bulk rather than ticketing them. This matches RFC 3834 guidance.