Welcome
At Second Sender we use AI to optimize your HubSpot emails for effortless A/B testing. Create improved subject lines and preview texts to send to your audience letting real results guide you to the best performer.
* This website and our app are independent of HubSpot, Inc., and are not authorized by, endorsed by, sponsored by, affiliated with, or otherwise approved by HubSpot, Inc..
TLDR Join Beta!HubSpot Native
Built directly into HubSpot. No external tools needed. Browse, test, and manage campaigns all within your familiar HubSpot interface.
Smart Filtering
Find the right emails to test with advanced filters. Search by open rate, click rate, send volume, or subject keywords to focus on your best candidates.
A/B Testing
Select any email from HubSpot and create subject line variants automatically. Test different subject lines to see which resonates best with your audience.
Real-time
Track open rates and click-through rates for each variant as they come in. Make data-driven decisions about which version performs best.
Choose Winners
After sufficient engagement time, declare a winner and send the best-performing variant to remaining contacts. Maximize results with proven subject lines and preview text.
Why Second Sender Exists
Re-engaging people who didn't open is one of the highest-ROI things a marketer can do. The problem: doing it right without a tool is brutally time-consuming.
Doing It Manually
- Find a good candidate email — filter by opens, clicks, and volume 5–15 min
- Segment your list by hand — subtract opens, clicks, and unsubscribes, create a new list, then split it into 4 equal groups 20–60 min
- Clone the original email 4 times, write new subject lines and preview text, attach a list to each, and send them 16–60 min
- Wait, compare results, choose a winner, assign the remaining list, and send 5–20 min
46 min – 2.5 hours per test
With Second Sender
- Pick your email using built-in performance filters 3–5 min
- AI generates new subject lines and preview text, builds and assigns recipient lists automatically 4 min
- Review and send — all test emails are ready to go 1 min
- Compare results in the dashboard and send the winner with one click 2 min
~11 minutes per test
Manual — 4 tests/month
~1.5 hrs/test → 6 hrs/month
$192/month in labor
Based on $32/hr for a HubSpot marketing admin
Second Sender — 4 tests/month
~11 min/test → 44 min/month
$39.95/month
More tests/month available on higher tiers
Save ~$152/month — 79% less than doing it by hand
How It Works
1. Select Email 3–5 min
Choose any HubSpot email to test. Use performance filters (opens, clicks, volume, keywords) to identify strong candidates.
2. Optimize Openers 4 min
SecondSender generates new subject line and preview text variants, then automatically builds recipient lists for each version.
3. Send Test 1 min
Review the content, send the control and variants, and watch opens and clicks update in real time.
4. Pick Winner 2 min
After two days of engagement, compare results and send the winning version to the remaining contacts.
Ready to Increase Revenue?
Start A/B testing with Second Sender today. Optimize subject lines and preview text to improve your open and click through rates!
Sign Up For Beta!