Email providers are suspicious when a lot of mail suddenly arrives from a domain or IP with no history. Warm-up means starting at low volume and raising it gradually as reputation builds.
Outfound manages this for you:
- A new sending domain starts at 20 emails a day and, with regular use, reaches 1,500 a day in about 15 sending days.
- The limit rises only when the daily allowance is actually used; if very little is sent for a long time, it steps back.
- If bounces or spam complaints rise, warm-up slows down or sending is paused.
- When moving to a new dedicated IP, traffic shifts gradually over about 6 weeks.
The domain card shows which warm-up day you are on and the current daily limit. You don't need a separate warm-up tool.