Warm-up and sending pace

What warming up means

Inboxes like Gmail, Yahoo and Outlook watch how a new sender's volume grows. A new account that sends thousands of emails at once looks like a spammer and lands in spam. One whose volume grows step by step, with few bounces and complaints, earns a reputation that gets its emails to the inbox.

So for the 30 days after its first campaign, your account sends gradually: each send goes out at full speed up to what your account has shown it can send cleanly, and a bigger one is spread over a few hours. If a list has a problem, it shows in the first hours instead of in every inbox.

How a send's pace is set

• From the start, up to 200 emails go out at once.
• Your proven volume is your largest campaign of the last 60 days whose bounces and complaints stayed low, counted a day after it went out, once they've come in.
• A send goes out at once up to your proven volume times 2 on the first day of the warm-up. That multiplier grows a little each day, to 5 on day 30.
• A bigger send goes out over 4 hours, plus 4 for each time it doubles that, 3 days at most. Its first emails leave right away, the last ones at the end, the others evenly between.
• Sends count together: what your other sends still have to send, or sent in the last 24 hours, adds to a new one, so splitting a send doesn't make it faster.

For example, a day after a clean send to 1,000 contacts, a send of up to about 2,100 goes out at once. A new account's first issue, to contacts it never emailed, goes out over:

Those times include the 3-hour check that follows the first slice of contacts you never emailed. First sends in steps

Where you see it

• The overview shows your day in the warm-up and how many emails go out at once right now.
• The send step says when an issue will be spread, and over how many hours. A send at full speed only shows your day in the warm-up.
• A campaign that is going out over hours says about how long it has left.

A scheduled issue follows the same pace from its send time. Paused and resumed, a send keeps its pace, and each step of a send to more contacts gets its own.

After the warm-up

After day 30, a send goes out at once up to 5 times your proven volume. A much bigger one, like a first send to a newly imported list, is still spread over hours, the same way. Each clean send raises your proven volume, so growing your list gradually keeps your sends fast.

Bounces and complaints matter during the warm-up and after it. Bounces, complaints and pauses