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.

How It Works

1. Select Email

Choose any HubSpot email to test. Use performance filters (opens, clicks, volume, keywords) to identify strong candidates.

2. Optimize Openers

SecondSender generates new subject line and preview text variants, then automatically builds recipient lists for each version.

3. Send Test

Review the content, send the control and variants, and watch opens and clicks update in real time.

4. Pick Winner

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!