Deliverability

This is where you end up after sending something and finding it did not arrive, or arrived in the wrong tab. Read SPF, DKIM and DMARC first, because authentication is the part you control and the part that has to be right before anything else helps. The promotions tab is a separate problem and not a fault. The rest of these answers are about the two things that decide the outcome after that: who is on your list, and how consistently you send.

• SPF, DKIM and DMARC, in plain English Three DNS records, what each one proves, and exactly what systeme.io hands you to paste.
• Why do my emails land in the promotions tab? Gmail decides this, not systeme.io. What shifts the odds, and why the tab costs less than it looks.
• What is a bounce, and what should I do about one? Hard, soft, and what the grey and blue addresses in your statistics are telling you.
• What is list hygiene, and why does it decide whether you get delivered? The weekly setting most accounts never switch on, and the open rate it protects.
• What is a warm-up period, and do I need one? The first 500 emails from a new account are already a warm-up, run for you.
• What is a spam complaint, and how many is too many? The denominator is opened emails, not sent. That changes the arithmetic a lot.
• Do I need a cookie banner? The help centre points at an outside tool. Where its script goes, and what it will not cover.
• Can I trust my open rate? The number systeme.io itself calls unreliable also decides who gets deleted.
• Can I put affiliate links in my emails? No rule mentions affiliate links. Several would catch one anyway.
• If I change my sending domain, do I start from scratch? Not from zero, but not free either. What actually resets when the domain changes.
• Can I use a sender name like Support or The Team? One article bans the pattern outright. Another uses almost the same name as its own working example.
• Can two systeme.io accounts send from the same domain? No. Authentication locks a domain to one account, and pending copies elsewhere are removed.