Deliverability, subject lines, welcome sequences and how to handle contacts who have not responded in a long time.
When a contact counts as inactive, what a reactivation looks like that does not read as desperation, and when deleting is required.
Why the open rate has measured little since automatic image preloading, and what actually decides whether a message gets opened.
How many attempts are defensible, at what intervals, and what separates helpful following up from irritating — with the stop rules.
Why four segments usually beat twenty — with the three characteristics worth separating on, and the question of when a segment stops being worth it.
Five messages with purpose, spacing and content — why the first has to arrive within minutes, and what must not appear in any of them.
SPF, DKIM and DMARC explained plainly: what the three records do, the order to set them up in, and why emails still fail to arrive when they are in place.
