Groundhogg vs Mailster (2026): which should you pick?
As of Nov 13, 2026, Groundhogg grades higher than Mailster: 2.0 against 1.8 out of 4.0.
Checked Nov 12, 2026 · graded Nov 13, 2026 by ToolGPA
Groundhogg grades higher on the free plan. Mailster grades higher on value for money. They get the same grade on features, ease of use and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
Groundhogg
Flat-rate CRM and email marketing plugin for WordPress
Which one is for you
Pick Groundhogg if
- Fits if you run WordPress sites and want contacts and email in the same place
- Works for agencies that want one licence across many client sites
Look elsewhere if
- Not for you if you are not on WordPress, as it only runs there
- Skip it if you want email sent for you, because sending needs an SMTP or sending service, and those integrations are listed from Pro
- Watch out: the vendor's price comparison assumes you host it yourself
- Watch out: a licence covers 1, 3, 5 or 25 sites by tier, and refunds are offered within 14 days of purchase
Pick Mailster if
- Fits if you already run WordPress and want your subscriber list kept in your own database
- Works for sites that send their latest posts or products to a list
Look elsewhere if
- Skip it if your site isn't on WordPress, because the plugin only runs there
- Tight if you want to send for free: there's no free edition and no trial
- Watch out: it renews at full price after the first year, and each licence covers one site
- Not for you if you don't want to set up a separate sending provider, since Mailster doesn't send the mail itself
- Tight if you need more than 3 automations, which is the Starter limit
How we grade them
| 2.0GPAGroundhoggFair | 1.8GPAMailsterWeak | |
|---|---|---|
| Value for money | CBasic is $20 a month for 1 site on annual billing ($240), inside the email category's middle band. Plus is $40 for 3 sites, Pro $50 for 5 and Agency $100 for 25. | B$79 a year for 1 site is about $6.60 a month, inside the cheaper quarter of email tools ($9.99). The first-year price is $39, then it renews at full price, and you pay your sending provider on top. |
| Free plan and trial | C14-day demo of Pro in a private WordPress sandbox, no credit card. No free plan. | FNo free edition and no trial. There's a demo and a 14-day money-back guarantee, which isn't the same thing. |
| Features | CContact management, broadcasts, automated flows, unlimited contacts, sales tools and an AI assistant connection. Sending needs an SMTP or sending service. | CNewsletters, drip emails, post-triggered sends, a template editor and segmentation. But Starter has 3 automations, and it doesn't send mail itself, so delivery depends on the provider you connect. |
| Ease of use | DNo store rating on record. It needs a WordPress site you host and set up, plus an email sender. | DYou need a WordPress site that you host and keep updated, plus an SMTP or email-service connection. No rating on record. |
| Platforms and integrations | BRuns only inside WordPress, with 7 integrations on record. | BWeb only, inside WordPress, but it connects to Mailgun, SendGrid, SparkPost, Mailjet, Gmail and Gravity Forms, among others. |
| Best for | a WordPress owner wanting CRM and email | newsletters sent from inside your own WordPress site |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Groundhogg and Mailster. How we grade
Price against what you get
Groundhogg starts at $20 a month and scores 2.0 out of 4 on features, ease of use and platforms. Mailster starts at $6.58 a month when paid by the year and scores 2.0.
They score the same, and Mailster starts $13.42 a month lower. Of the other email marketing and newsletter tools on the chart, 28 score higher than Groundhogg for less, and 3 score higher than Mailster for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Groundhogg is open source and self-hostable, according to its own site.
- Groundhogg also covers sales pipeline and AI agents.
- Mailster also covers templates, forms and rSS reader.
At a glance
| Groundhogg | Mailster | |
|---|---|---|
| Pricing | Free trial | Paid |
| Starts at | $20 per month for 1 site, billed annually ($240) | $79 per year for 1 site, renewing at full price after a first-year price of $39 |
| Free plan | None | None |
| Free trial | 14-day free demo of the Pro plan in a private WordPress sandbox, no credit card | None listed |
| Web | ||
| Made by | Groundhogg Inc. | Mailster |
| Price read from | groundhogg.io | mailster.co |
| Checked | Nov 12, 2026 | Nov 12, 2026 |
Worth knowing
Groundhogg
- It runs only inside WordPress; the vendor's price comparison assumes you host it yourself.
- Sending email needs an SMTP or sending service. SMTP and SMS integrations are listed from Pro.
- A single licence covers 1, 3, 5 or 25 sites depending on the tier.
- Refunds are offered within 14 days of purchase.
Mailster
- It runs only inside WordPress, and every licence covers one site or domain.
- There is no free edition; the site offers a demo and a 14-day money-back guarantee.
- Updates and support need an active licence. The plugin keeps working after expiry, but renewals are at full price.
- Mailster does not send mail itself. Deliverability depends on the email provider or server you connect, and the vendor recommends a dedicated provider.
Key features
Groundhogg
- Contact management
- Contact records with tags, custom fields, notes, tasks, activity timelines, saved searches and segments inside the WordPress dashboard.
- Email broadcasts
- Send broadcasts, batch large sends and handle bounces and complaints; bounce handling is a Pro feature.
- Automated flows
- Build automations that move contacts through sequences. Conditional logic needs Pro.
- Unlimited contacts
- The vendor says it never charges more for extra contacts, users, flows or email sends.
- Sales tools
- Booking calendar, lead scoring, content restriction and a sales pipeline from the Plus tier up.
- AI assistant connection
- Connect Claude or ChatGPT to the CRM over MCP so an assistant can work with contacts and flows.
Mailster
- Newsletters and automation
- Send newsletters, welcome emails, birthday emails, drip campaigns and autoresponders. The number of automations depends on the tier.
- Send your latest posts
- Send new posts, products, events or other custom post types, and use them to trigger automations.
- Editor and templates
- A drag-and-drop editor with more than 400 free and premium templates.
- Any sending provider
- Mail can go out through SMTP or an email service provider; integrations are available for services such as Mailgun, SendGrid, SparkPost, Mailjet and Gmail.
- Segmentation and tracking
- Segment subscribers and track opens, clicks, email providers and locations from within WordPress.
- Precheck
- A pre-send check that flags issues in a campaign, capped at 10, 100 or 1,000 runs a month by tier.
Plans
Groundhogg
Basic$20
per month for 1 site, billed annually ($240)
Premium support, basic add-ons, premium flow steps and superlinks. No company records, booking calendar or sales pipeline.
Plus$40
per month for up to 3 sites, billed annually ($480)
Adds form plugin integrations, sales, CRM and marketing add-ons, company records, booking calendar, lead scoring and sales pipeline.
Pro$50
per month for up to 5 sites, billed annually ($600)
Adds SMTP, SMS, ecommerce and membership integrations and conditional logic.
Agency$100
per month for up to 25 sites, billed annually ($1,200)
Adds white-label branding, all integrations and all add-ons, and permits use for clients.
Mailster
Starter$79
per year for 1 site
Unlimited subscribers, 3 automations, 10 prechecks a month, 10 free templates. $39 for the first year in a Black Friday listing; renewals at full price.
Professional$99
per year for 1 site
Adds 10 automations, 100 prechecks a month and 7 premium templates. Shown at $49 for the first year in a Black Friday listing, with renewals at the full price.
Agency$199
per year for 1 site
Unlimited automations and 1,000 prechecks a month. Shown at $99 for the first year in a Black Friday listing, with renewals at the full price.
Ways to pay less
Groundhogg
- Nonprofit
50% off for registered nonprofits
A grant gives registered nonprofits 50% off annual licenses for Groundhogg Pro, MailHawk and HollerBox. It does not renew automatically, so it must be re-applied for each year.
Mailster
- Other savings
First-year price in a Black Friday listing
The pricing page currently shows $39, $49 and $99 for Starter, Professional and Agency, against $79, $99 and $199 regular prices, and states that renewals are at full price. It gives no end date.
Common questions
Which is cheaper, Groundhogg or Mailster?
As of Nov 12, 2026, Mailster is cheaper to start with: $6.58 a month when paid by the year, against $20 a month for Groundhogg. Groundhogg starts at $20 per month for 1 site, billed annually ($240), and Mailster starts at $79 per year for 1 site, renewing at full price after a first-year price of $39.
Which has a free plan, Groundhogg or Mailster?
As of Nov 12, 2026, neither Groundhogg nor Mailster has a free plan. Groundhogg has a free trial.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.