Shared-inbox after-hours SLA: who owns a reply that lands overnight

Positive replies do not respect your agency's closing time. A prospect who writes at 11:40pm still expects a human path in the morning, and "someone will see it" is how overnight threads die in a shared inbox.

GTM routes replies into a shared inbox per client workspace and stops the sequence on reply. That stops the robot from stacking more mail. It does not decide who owns the human response when the message arrived outside business hours.

The overnight ownership problem

Three failure modes show up again and again in shared mailbox ops:

1. Ownership vacuum: everyone can see the thread, so nobody claims it.
2. Duplicate dawn reply: two people both draft at 9:05am.
3. Fake SLA satisfaction: an auto-ack fires overnight and the dashboard looks green while no human has answered.

Missive's shared mailbox guidance is blunt on the third point: auto-responses usually do not stop the SLA timer. The clock started when the customer message landed. Business hours settings only help if they match the hours your team actually works.

Define business hours per client, not per agency myth

Agencies often run multiple client time zones inside one ops team. Write the SLA in the client workspace:

• Client business hours (and whose zone: client HQ vs agency desk)
• Agency coverage hours for that client
• Whether overnight positive replies are "next business morning" or "follow-the-sun"
• What counts as first meaningful response (human reply that advances booking, not "got it")

If the tool measures SLA in business hours, configure those hours to reality. A dashboard set to 8–6 while the team works 7–5 creates two hours of fiction every day.

Name the overnight owner before the reply arrives

Pick one model and put it in the client brief:

• Next-open owner: a named seat (or rotating seat) owns anything that arrived after close, reviewed first thing in coverage hours.
• On-call escalation: only for clients who paid for after-hours coverage; page a human for "book me this week" class intent.
• AI hold + morning handoff: AI may acknowledge only if the client approved that path, then force assignment to a human before the SLA can clear.

For most agency outbound motions, next-open owner is enough. On-call is a commercial choice, not a default.

Whatever you pick, assignment must be explicit. Visibility is not ownership.

What should happen to the SLA clock overnight

Recommended default for outbound positive replies:

1. Sequence already stopped on reply.
2. Thread lands in the client shared inbox unassigned or pre-routed to the overnight bucket.
3. SLA timer uses business hours, so overnight wall-clock time does not burn the breach budget.
4. At coverage open, unassigned overnight positives sort above routine nurture replies.
5. First human reply that owns next steps stops or satisfies the first-response SLA, depending on how your tool defines it.
6. Booking handoff follows the client's calendar ownership rules.

Know which action your tool treats as SLA-complete. Some stop on reply. Others require assign, close, or resolve. A late-night "I'll check tomorrow" from the wrong person can steal ownership without finishing the job.

Priority inside the morning pile

Not every overnight message is equal. Triage order that works for agency outbound:

1. Explicit meeting ask or calendar link request
2. Clear buying question (pricing, scope, timing)
3. Soft interest that needs a clarifying question
4. OOO or bounce-like auto traffic (reclassify, do not burn AE time)
5. Unsubscribe / not interested (honor fast, no debate)

OOO and bounce categories belong on a separate board so they do not consume the human SLA queue.

Write the after-hours clause into the client ops packet

Include:

• Coverage hours and time zone
• Overnight owner seat or rotation calendar
• Escalation path for "wants to buy now"
• Whether auto-ack is allowed
• What stops the SLA timer
• Handoff rule into AE calendar ownership

Review it when the client changes AEs or when the agency changes who sits the morning queue.

Where this sits with GTM

Isolated client workspaces keep one client's overnight pile from mixing with another's. Shared inbox reply ownership and calendar SLAs only work if after-hours rules are written down. Otherwise the system did its job (stop sequence, surface reply) and the humans still dropped the ball between 7pm and 9am.

Overnight replies are not a tooling mystery. They are an ownership contract. Name the seat, configure the clock, and clear the morning queue in priority order.

Sources: Missive shared mailbox best practices, Lamdesk support operations overview, GTM product knowledge.