GMass
GMass is a powerful email marketing and cold email solution that works directly inside your Gmail account to help you send mass campaigns and automated follow-ups easily.
Email on Acid
Email on Acid is a comprehensive email pre-deployment platform providing automated testing, content checking, and deliverability tools to ensure your campaigns look perfect across all major inbox providers.
Quick Comparison
| Feature | GMass | Email on Acid |
|---|---|---|
| Website | gmass.co | sinch.com |
| Pricing Model | Freemium | Subscription |
| Starting Price | Free | $74/month |
| FREE Trial | ✘ No free trial | ✓ 7 days free trial |
| Free Plan | ✓ Has free plan | ✘ No free plan |
| Product Demo | ✓ Request demo here | ✓ Request demo here |
| Deployment | ||
| Integrations | ||
| Target Users | ||
| Target Industries | ||
| Customer Count | 0 | 0 |
| Founded Year | 2015 | 2009 |
| Headquarters | Chicago, USA | San Antonio, USA |
Overview
GMass
GMass turns your regular Gmail or Google Workspace account into a full-featured email marketing platform. You can send mass emails, create complex mail merges using Google Sheets data, and schedule automated follow-up sequences that stop once a recipient replies. It lives entirely inside your Gmail interface, so you don't have to learn a new dashboard or export your contacts to external software.
You can use it to bypass Gmail's sending limits by connecting to external SMTP services or stay within standard limits for smaller outreach. It solves the problem of low engagement by making every mass email look like a personal, one-on-one message. Whether you are a recruiter, salesperson, or non-profit organizer, you can manage your entire outreach strategy without ever leaving your inbox.
Email on Acid
Email on Acid helps you eliminate the guesswork of email marketing by previewing your campaigns across over 100 different email clients and devices. You can catch rendering issues, broken links, and accessibility problems before you hit send, ensuring every subscriber has a consistent experience. The platform automates the tedious manual testing process, allowing your team to deploy high-quality emails faster and with more confidence.
Beyond simple previews, you can optimize your inbox placement with deliverability tools that check your IP against blacklists and validate your SPF and DKIM records. Whether you are a solo developer or part of a large enterprise marketing team, the platform provides the technical insights needed to bypass spam filters and improve engagement. You can integrate these checks directly into your existing workflow to maintain brand standards across every communication.
Overview
GMass Features
- Google Sheets Integration Connect your spreadsheets directly to Gmail to personalize every email with custom data fields from your rows.
- Automated Follow-ups Set up a sequence of emails that send automatically until your recipient replies, clicks, or opens your message.
- Email Reporting Track opens, clicks, and replies in real-time with detailed analytics reports generated right inside your Gmail account.
- Behavior-based Campaigns Send new emails specifically to people who opened or clicked your previous messages to maximize your conversion rates.
- Scheduling Draft your emails now and schedule them to go out at the exact time your prospects are most active.
- List Segmentation Filter your mailing lists based on past engagement to ensure you only message the most relevant contacts.
Email on Acid Features
- Unlimited Email Previews. View your email exactly as it appears on 100+ combinations of devices and clients to ensure perfect rendering every time.
- Campaign Precheck. Run an automated checklist to verify links, images, and accessibility standards so you never miss a critical error.
- Spam Testing. Test your emails against 23 different spam filters to identify potential delivery issues before they impact your open rates.
- Email Editor. Make real-time code changes in a live editor and see instant updates across all previews without re-uploading your files.
- Accessibility Checks. Optimize your emails for screen readers and visually impaired subscribers with automated ADA compliance suggestions and color contrast adjustments.
- Image Validation. Check for missing alt text and optimize file sizes to ensure your images load quickly and convey meaning effectively.
Pricing Comparison
GMass Pricing
- Up to 50 emails per day
- All standard features included
- Gmail-based sending
- Basic campaign tracking
- GMass branding on emails
- Everything in Free, plus:
- Unlimited email sending
- No GMass branding
- Basic mail merge features
- Address verification tool
- Email support
Email on Acid Pricing
- 1 user seat
- Unlimited email previews
- Campaign Precheck
- Email editor
- Accessibility testing
- Standard support
- Everything in Basics, plus:
- 3 user seats
- Spam testing
- Deliverability insights
- Advanced analytics
- Priority support
Pros & Cons
GMass
Pros
- No new software to learn since it lives in Gmail
- Powerful Google Sheets integration for easy personalization
- Reliable automated follow-up sequences increase reply rates
- High deliverability by using Google's own mail servers
- Simple setup process takes less than a minute
Cons
- Requires Google Chrome to use the browser extension
- Interface can feel cluttered inside the Gmail window
- Daily sending limits are tied to Google's restrictions
Email on Acid
Pros
- Unlimited testing allows for frequent iterations without extra costs
- Fast rendering speeds for quick campaign turnarounds
- Comprehensive accessibility tools ensure inclusive marketing
- Intuitive interface makes it easy for non-technical users
Cons
- Higher starting price point than some basic competitors
- Spam testing is restricted to higher-tier plans
- Occasional lag when loading a large number of previews