IP Warmup Schedule — Ramping a New Sending Server in AcelleMail

Why a new IP needs ramping#

When you provision a new sending IP — fresh Amazon SES verified domain, new Postmark account, new dedicated IP from your ESP — receiving servers (Gmail, Outlook, Yahoo) have NO reputation data on it yet. Their default treatment of unknown IPs is conservative: messages from a brand-new IP at high volume look like a botnet, so they go to spam or get rejected.

Warmup = sending in small batches at first, growing volume daily over 4-6 weeks. Each successful batch teaches the receiving servers "this IP sends legitimate mail at this volume." Once you've earned a baseline reputation, full volume is sustainable.

Skip warmup → blocked or filtered for months until reputation recovers from a fresh start.

The realistic 30-day ramp table#

Send to your MOST engaged segment first. Engaged-last-7d is the gold subgroup; expect 30-40% open rates. Receiving servers see high engagement → reputation jumps fast. If you start with re-engagement segments (low open rate), warmup takes 2-3× longer.

Configure the schedule in AcelleMail#

Open the sending-server detail#

In AcelleMail's sidebar, click Sending → Sending servers. The list shows every server connected to this account with its status chip, sending limit, and last activity:

Click into the row you want to configure. The detail page surfaces Connection settings (host / credentials), Configuration (server name, default from, sending limit, bounce + FBL handler), and the Test connection / Send test email buttons in the toolbar:

Where the throttle lives#

Same sending-server detail → Configuration section. The Sending limit dropdown caps how many emails AcelleMail will hand to this server per unit of time (per minute / hour / day):

AcelleMail enforces the limit globally — when the rolling-window counter hits the cap, the queue holds back until the window slides. No throttling code in your campaigns; configure once per server.

For warmup specifically: set Sending limit to 1,000/day on Day 1. Each day raise it manually following the table above, OR use AcelleMail's per-server Warmup strategy (admin panel) to automate the daily increment.

Admin-side: pool-wide warmup view#

The admin pool list lets you see every server's warmup state at a glance:

In the admin sidebar, Warmup Strategies lets you define reusable warmup templates and attach them to servers as they're provisioned. The Strategies screen ships with 4 starter templates (Cautious / Balanced / Aggressive / Long-Haul) — each defines starting volume, daily increment, per-day cap, and growth curve:

Click into any preset to see its per-day volume table + risk-level + estimated completion. Balanced is the recommended default — linear ramp + safety pause if bounce/complaint signals trip. For a new IP with no prior reputation, the Cautious strategy (slow ramp + extra checkpoints) buys deliverability insurance. For a known-good IP on a new account, Aggressive cuts the warmup to ~30 days.

The per-server Warmup stats view shows live progress against the assigned strategy:

Monitoring during warmup#

Daily checks (5 minutes):

1. Bounce rate at the AcelleMail campaign report. Should stay <2%. If creeps to 3%+, HOLD the ramp at current volume; don't raise tomorrow.
2. Complaint rate. Stay <0.1%. If >0.15%, HOLD or cut volume.
3. Google Postmaster Tools (added separately, see walkthrough). IP reputation should climb from "Bad" → "Medium" → "High" over the warmup. If stays "Bad" after Day 14, content + list quality issue, not just volume.
4. SNDS (Outlook postmaster, see walkthrough). Per-IP reputation Green/Yellow/Red. Aim for Green by Day 21.

What to do if warmup hits a wall#

Common UI signals + fixes#

-- AcelleMail subscriber tagging by recipient ISP
UPDATE subscribers SET tags = JSON_ARRAY_APPEND(tags, '$', 'gmail') WHERE email LIKE '%@gmail.com';
UPDATE subscribers SET tags = JSON_ARRAY_APPEND(tags, '$', 'outlook') WHERE email LIKE '%@outlook.com' OR email LIKE '%@hotmail.com' OR email LIKE '%@live.com';

# Daily cron at 02:00 — increments per-server quota by 20-30% if yesterday's
# bounce + complaint rates stayed green
SERVER_UID="..."

# Yesterday's stats from API
stats=$(curl -sH "Authorization: Bearer $ADMIN_TOKEN" \
  "https://acellemail.com/api/v1/admin/sending-servers/${SERVER_UID}/stats?day=yesterday")

bounce=$(echo $stats | jq '.bounce_rate')
complaint=$(echo $stats | jq '.complaint_rate')
current_limit=$(echo $stats | jq '.daily_sending_limit')

# Stop ramp if signals red
if (( $(echo "$bounce > 0.04" | bc -l) )) || (( $(echo "$complaint > 0.0015" | bc -l) )); then
  echo "Holding ramp — bounce=$bounce complaint=$complaint"
  exit 0
fi

# Else raise quota 25% (cap at full-volume target)
new_limit=$(( current_limit * 5 / 4 ))
if [ $new_limit -gt 250000 ]; then new_limit=250000; fi

curl -X PATCH -H "Authorization: Bearer $ADMIN_TOKEN" \
  -d "{\"sending_limit\": $new_limit}" \
  "https://acellemail.com/api/v1/admin/sending-servers/${SERVER_UID}"

echo "Raised limit to $new_limit"

Related articles#

• Configuring multiple sending servers
• Sender reputation monitoring
• Sending throttling strategies
• IP warmup by ISP
• Gmail postmaster tools walkthrough
• Microsoft SNDS walkthrough