GMass

GMass turns your Gmail into an email marketing and cold email platform. Hit Compose, enter your list, subject, and message, and GMass sends individually personalized emails using mail merge—powered live by Google Sheets, so you can say goodbye to CSV files. It runs as a Chrome extension and works entirely inside Gmail, with no separate dashboard to learn.

What it does

Beyond bulk sending, GMass handles automatic follow-up sequences until recipients reply, behavior-based campaigns (such as targeting everyone who opened or didn't click a prior send), and free email list verification to protect deliverability. Reply and bounce handling is automated, and campaign-level reports show opens, clicks, replies, and bounces right inside Gmail on desktop or the mobile app.

Best for

Salespeople running cold outreach from Gmail, recruiters sending bulk personalized emails, and small businesses managing campaigns without a dedicated ESP. GMass is trusted by 300,000+ users with 5-star reviews.

• Mail Merge with Google Sheets — Personalize live from any spreadsheet column, with auto-detected fallback values
• Automatic Follow-Ups — Send sequences until a recipient replies to boost response rates
• Email List Builder — Find addresses buried in your Gmail just by searching
• Behavior-Based Campaigns — Re-target segments like openers or non-clickers from past sends
• Reply Management — Auto-categorize replies and bounces to keep your inbox clean
• Campaign Reporting — Track opens, clicks, replies, and bounces inside Gmail
• Scheduling & A/B Testing — Schedule or repeat sends and test subject lines or content