Don't Torch Your Domain

You are an email deliverability engineer advising a residential solar installer
who is about to email a large list of past customers and old leads for the first
time in years.

### MY SITUATION
Primary domain (quotes, contracts, day-to-day): [domain]
Email provider: [Google Workspace / Microsoft 365 / other]
List size: [n]
Oldest contact: [year]
Sending tool I plan to use: [or "not chosen yet"]
Have I ever sent bulk email from this domain: [yes/no]

### GIVE ME

1. SENDING DOMAIN STRUCTURE. What to send bulk from versus transactional,
   and exactly how to set it up. Explain why the separation matters in terms of
   what I actually lose if I get it wrong.

2. AUTHENTICATION. SPF, DKIM, and DMARC — what records I need, what the DMARC
   policy should be for a new sending subdomain, and how to check what I already
   have. Warn me about the SPF lookup limit.

3. WARM-UP SCHEDULE. A day-by-day ramp from zero to my full list size, given my
   list is cold. Tell me what volume to start at, how fast to increase, and what
   metric should make me stop and reassess.

4. LIST HYGIENE BEFORE FIRST SEND. What to remove or verify first. My oldest
   contacts are years stale and some addresses no longer exist. Tell me what
   bounce rate is survivable and what will get me blocked.

5. ENGAGEMENT SEQUENCING. Which segments to send to first so early engagement
   is good, and which to hold back until reputation is established.

6. THE STOP CONDITIONS. Specific numbers — bounce rate, complaint rate, and
   what to do if I hit them mid-campaign.

### RULES
- Be specific and current. Name the actual records and the actual thresholds.
- Where major mailbox providers publish requirements for bulk senders, say so
  and tell me where to verify — do not rely on my memory or yours.
- If my situation calls for a dedicated IP, say so; if it does not, say that too.

### OUTPUT
A setup checklist in order, a warm-up table (day | volume | segment | watch for),
and the stop conditions as a short list I can pin up.

You are advising a US residential solar installer on legal and practical
compliance for emailing past customers and old leads.

### MY SITUATION
States I operate in: [list]
List composition: [past customers / old quotes / purchased lists?]
Oldest contact: [year]

### GIVE ME

1. What CAN-SPAM actually requires on every message I send — the concrete list.
2. How unsubscribes must be handled, including the timeframe, and what
   "honouring" means in practice across multiple sending tools.
3. Whether my state adds anything beyond federal requirements.
4. How to build a suppression list that survives me changing sending tools —
   this is the one that bites people.
5. Whether prior customers and old quote recipients sit differently from cold
   contacts, and what that changes.
6. If any part of my list was purchased rather than earned, say plainly what the
   risk is and whether to send to it at all.

### RULES
- This is practical guidance, not legal advice, and you should say so.
- Do not soften a real requirement into a best practice.
- If SMS is in scope, flag that it is governed separately and more strictly.

### OUTPUT
A compliance checklist, a suppression-list schema, and a short list of things
that would genuinely get me in trouble.