Sending from your main domainCold volume produces complaints and bounces at rates normal marketing does not. Run it on a separate domain that redirects to your main one, with its own authentication and its own reputation. If it gets damaged you change domains; if you had been sending from the primary, you have lost your invoices, your password resets and your newsletter along with it.
Skipping verificationCold lists decay fast, and a hard bounce rate above a couple of percent is read as a sender who does not know who they are emailing. Verify before the first send, not after the first campaign tells you. This is the cheapest single thing you can do to keep a cold programme alive.
Volume before warmupA new domain sending several hundred emails on day one looks exactly like a compromised account, because that is what compromised accounts do. Ramp over weeks from a low daily figure, and keep a per-address ceiling in place permanently rather than only during warmup.
Assuming the US rules apply everywhereCAN-SPAM permits unsolicited commercial email with an opt-out and a physical address. Canada's CASL requires consent, express or implied, with real penalties. In the EU and UK, business-to-business cold contact turns on lawful basis and the ePrivacy rules, and the analysis differs by member state. Australia's Spam Act requires consent, again with an inferred-consent route. Determine the obligation from where the recipient is, not where you are.
Personalisation that is obviously automated'I loved your recent post about {{topic}}' with the merge tag showing, or a first line assembled from a scraped headline, is worse than no personalisation — it tells the recipient they are one of thousands. If the research cannot be done, narrow the list until it can.
Mixing outreach into the marketing accountCold replies, complaints and bounces have no business touching the sending reputation of the list that people actually opted into. Separate domains, separate sending, separate suppression. The one thing that must be shared is the suppression list — an opt-out anywhere has to be honoured everywhere.