Sender Review 2026: The Free Plan Is Real, and So Is the List of Who Cannot Use It
The Best: Customer service 4.9, the highest sub-score measured on this site
The Worst: Eight verticals banned by name, and no independent deliverability figure at all
The short version
Sender is the most generous free plan on this site that still includes the things people actually need: 2,500 subscribers, 15,000 emails a month, automation, an API and an SMTP relay, with no credit card. Most free tiers in this category withhold automation or the relay. Sender withholds neither.
It also has the highest customer service sub-score we have measured anywhere: 4.9 out of 5 on Capterra, above SMTP2GO and EmailOctopus at 4.8. And it publishes an official MCP server with OAuth, forty tools and a rate limit its own documentation describes as “an agent-runaway backstop”, which is a level of care almost nothing else here shows.
Two things pull it back. The first is that no independent measurement of Sender deliverability exists anywhere. It has never been in a seedlist panel and has no page on the second panel. The second is the anti-spam policy, which bans eight named verticals outright and terminates accounts “without notice and no refund” above a 0.1 percent complaint rate. That is a defensible way to run a network. It is also a real risk if your list is anything other than clean and opted in.
Three ratings, and one of them measures something else
Sender carries a 4.9 on Trustpilot across 1,388 reviews. That is the highest volume-plus-score combination of any platform we cover, and it should be the strongest evidence in this review. We read twenty of those rows and we do not think it means what it appears to mean.
Seventeen of the twenty name a support agent by first name. Four names recur: one appears in at least eight rows, another in at least five, a third in at least three, a fourth in at least two, and they recur across reviewers writing from unrelated countries. All twenty rows fall within roughly twelve days of each other.
That is the signature of a post-chat solicitation funnel: a support conversation ends, the agent asks for a review, the customer writes about the agent. It is a normal and legitimate practice. It also means the corpus is measuring satisfaction with a support interaction, not satisfaction with the product.
We are careful about how far this goes. We read twenty rows out of 1,388, so this is a description of the sample we read, not a proven claim about the whole corpus. But the pattern in those twenty is strong enough that we do not blend the Trustpilot 4.9 with the Capterra 4.7, and neither should you. They are measuring different things.
The Capterra corpus behaves normally. We read 50 of its 211 rows, spread across dates and industries, praising and complaining about the product itself. One defect worth noting: a reviewer named Oliver P. has his Pros text repeated verbatim in his Cons field. That is a listing artefact, not a fabrication, and it is one row out of fifty.
G2 shows 4.7 from 274 and renders no individual reviews at all. We read zero and quote nothing from it.
Snapshot
| Legal entity | “The Service is owned and operated by UAB Sender.lt, located at Lvivo st. 25, Vilnius, Lithuania.” |
|---|---|
| Founded | 2012, stated on the about page. Copyright runs 2012 to 2026, so nothing is stale. |
| Size | “32 team members” and “180,000+ happy customers” |
| Founder | “Edgaras Founder and CEO of Sender”. First name only. No surname is published anywhere on the site. |
| Registration number | Not published. Unusual for an EU company: we checked the terms, the privacy policy, the about page and the footer. |
| Free plan | “Up to 2 500 subscribers”, “Up to 15 000 emails/month”, “No credit card required. No hidden fees.” |
| Paid entry | Standard $7/mo, billed $84 for the first year. Professional $14/mo, billed $168 for the first year. Enterprise is custom. |
| Pay as you go | $5.80 per 1,000 emails |
| Subscriber counts on paid plans | Not published as a fixed tier. The pricing page is slider-driven and $7 and $14 are the slider defaults, not plan ceilings. We do not publish a subscriber count against either price. |
| Dedicated IP | “1 included*” on Professional and Enterprise. “No” on Free and Standard. |
| Compliance | Footer claims “GDPR Compliant” and “ISO Certified”. No ISO standard number or scope is given, and SOC 2 appears nowhere. |
One live defect worth flagging to anyone doing compliance diligence: the /gdpr/ page linked from the site footer returns a 404. The claim is in the footer, the page behind it is gone.
Who is not allowed to use Sender
This is the section we would read first if we were choosing this platform, and it is the one most reviews skip. Sender publishes a genuine anti-spam policy with a named list. Quoted from it, the prohibited categories are:
| Banned outright | “Affiliate marketing” · “Gambling, betting” · “Forex, stock trading tips, get rich quick, work at home, etc.” · “Pornography, escorts, dating services” · “Drugs, male enhancement pills, etc.” · “solo email ads” · “Loans” · “Weight loss products” |
|---|---|
| Not on the list | Cryptocurrency, CBD, firearms, debt collection and MLM are not named. We report that as an absence from the list, not as permission. Ask before you build on it. |
| Complaint threshold | Spam reports above 0.1 percent for lists over 1,000 subscribers, capped at 50 a day |
| Automatic triggers | “Any spamtrap hits, SpamCop reports or abuse complaints” and a hard bounce rate “exceeds 10%” |
| Consequence | “your account will be terminated without notice and no refund will be provided.” |
Enforcement is real, and the corpus shows it firing on cold B2B outreach rather than on obvious spam. One reviewer, writing in August 2025 at one star, describes sending to publicly available business contacts and being “suspended without prior notice”, adding that the “anti-spam policy is unclear and not well-communicated during onboarding”. A second reviewer, who gave five stars and was otherwise positive, still wrote “it wasn’t very clear to me why my account was suspended”. A Trustpilot one-star row describes an account shutdown.
Note what those three have in common: not that Sender enforced, but that it did not explain. The complaint is about communication, not about the rule.
The refund policy makes that risk worse
Sender publishes one of the most restrictive refund clauses in this category, and all three of its parts matter:
- “We are required to provide a refund only if we terminate our Services to you without cause before the end of a year for which you have paid.”
- “We do not provide refunds if your account is suspended because of violation of our Anti-Spam Policy or Terms of Use.”
- “We do not refund any unused or partially used plans (monthly or yearly)”, including if you “forgot to cancel your plan”.
There is no money-back guarantee, no cooling-off period and no pro-rata. Combine that with termination without notice above a 0.1 percent complaint rate and the practical position is clear: if you pay annually and get suspended in month two, the money is gone. Buy monthly until you are confident in your list.
SMTP settings
Fully documented, and confirmed on two independent vendor pages.
| Setting | Value |
|---|---|
| Hostname | smtp.sender.net |
| Ports | 25, 2525, 587 |
| Recommended | “Port 587 with TLS is recommended” |
| Fallback | “Use port 2525 as a fallback if port 587 is blocked” |
| Authentication | “Authentication: PLAIN or LOGIN over TLS” |
| Port 465 | Not offered. There is no implicit SSL port. |
| Prerequisite | A verified sending domain with SPF, DKIM and DMARC in place |
| Messages per connection | Not published. We checked four documentation pages. |
Requiring DMARC before you can send is a good sign. It is the single most effective thing a provider can insist on after the 2024 bulk sender requirements, and several platforms on this site still treat it as optional.
The API, and an MCP server that has clearly been thought about
The API base is https://api.sender.net/v2/, sending is a POST to /v2/message/send, and authentication is a bearer token. Rate limiting is enforced per minute and surfaced properly through X-RateLimit-Limit and X-RateLimit-Remaining headers, with 429 and Retry-After on breach, shared across all tokens on an account.
Two caveats. The numeric ceiling is not published: the figure that appears in the documentation is an illustrative example, not a stated limit, and we do not repeat it as one. And there is only a JavaScript SDK. No Python, Go, Ruby, PHP or Java client is offered.
It runs at https://mcp.sender.net/mcp over Streamable HTTP with JSON-RPC 2.0, authenticates with an OAuth 2 bearer token scoped mcp:use, and exposes forty tools.
Two details are worth quoting because almost nobody else does this. Workflow creation is throttled to 50 a day per account, described in the documentation as “an agent-runaway backstop”. And: “Destructive operations name their blast radius and require an explicit flag.” That is somebody who has thought about what happens when an autonomous agent is pointed at a mailing list.
Deliverability, where there is nothing to measure
We looked for a figure and there is not one.
Sender is not in the EmailToolTester panel. We verified this specifically because the panel page displays percentages for other platforms and it would be easy to attach one to Sender by mistake. The sixteen ESPs in that table do not include it. Any inbox placement percentage attributed to Sender from that source would be fabricated, and we have caught exactly that kind of error twice in this project.
The second panel returns a 404 for Sender at its per-platform URL.
So the deliverability score below rests on structure rather than measurement. In Sender’s favour: mandatory SPF, DKIM and DMARC before sending, a dedicated IP on Professional and Enterprise, an enforced 0.1 percent complaint ceiling, and a hard bounce ceiling of 10 percent. Those are the practices that produce good placement. Against: none of it has been checked by anyone outside the company, and the corpus contains no volume of deliverability complaints either way.
Ratings breakdown
Six categories, each out of 10, judged against the same evidence rules on every platform we cover. The overall is the unweighted arithmetic mean, rounded to one decimal: 8.0 + 7.5 + 5.5 + 8.0 + 7.5 + 7.5 = 44.0, divided by 6, equals 7.3.
Ease of use, 8.0. Capterra ease of use 4.6 across 211 reviews, and the fifty rows we read are consistent about it. A clean builder, popups and landing pages included, nothing that needs a tutorial.
Automation, 7.5. A real automation builder, segmentation and SMS, and crucially it is on the free plan, which is rare. Held below 8 because the platform is not trying to compete with ActiveCampaign or Klaviyo on flow depth, and does not claim to.
Deliverability, 5.5. No independent measurement exists, from any panel, at any date. Held at 5.5 rather than lower by mandatory DMARC, an enforced complaint ceiling and a dedicated IP option, which are the right structural choices.
Support, 8.0. A Capterra customer service sub-score of 4.9, the highest we have recorded on this site, across 211 reviews. Twenty-four seven email and live chat, on the free plan. Held below 8.5 because three separate reviewers describe suspensions that were enforced without explanation, which is a support failure even when the enforcement was correct.
Pricing value, 7.5. A free plan with automation, API and SMTP included is worth more than most paid entry tiers here, and $5.80 per thousand pay as you go is competitive. Held down by a refund policy with no pro-rata and no refund on suspension, and by paid subscriber counts that the pricing page does not state.
API and MCP, 7.5. An official MCP server with OAuth, forty tools and a documented agent-runaway backstop, which is better than most of this category manages. Held down by a single SDK and by a rate limit that is enforced but never numerically published.
Who should use Sender, and who should not
Sender is the right call for
Look elsewhere if
Third-party validation
| Source | Score | Volume | Notes |
|---|---|---|---|
| Capterra | 4.7 / 5 | 211 reviews, 50 read | Ease of use 4.6, customer service 4.9. Product ID 139770, verified to resolve to Sender. Features and value for money sub-scores did not reproduce on a second read and are not published here. |
| G2 | 4.7 / 5 | 274 reviews, 0 read | Individual reviews are not rendered. No sub-scores reproduced. We quote nothing from G2. |
| Trustpilot | 4.9 / 5 | 1,388 reviews, 20 read | 93 percent five star, 3 percent one star. Discounted: 17 of the 20 rows we read name a support agent, four names recur across unrelated countries, all 20 fall within about twelve days. Read as support-interaction satisfaction, not product satisfaction. |
| Inbox placement | No figure | – | Absent from the EmailToolTester panel; the second panel returns 404 for Sender. |
We never add these into a single denominator. Where this review says something is named by reviewers, it means named in that many of the rows we actually read, and the row count is stated every time.
Top 3 alternatives
| Alternative | Our score | Take it instead if |
|---|---|---|
| MailerLite | 7.4 | You want the same simplicity with a measured 89.8 percent inbox placement behind it. The single thing Sender cannot offer. |
| Brevo | 7.7 | You need marketing and a documented SMTP relay billed on sends rather than on stored contacts, from the highest-scoring platform we cover. |
| EmailOctopus | 7.1 | You want the cheapest credible paid tier in the category, with Capterra sub-scores of 4.8 earned steadily over years. |
Continue reading
- Sender pricing, the free plan and the pay-as-you-go rate
- Sender API, endpoints, bearer auth and the MCP server
- Sender integrations
- MailerLite review
- Brevo review
- EmailOctopus review
Frequently asked questions
Is Sender free?
Yes, permanently. The Free Forever plan covers up to 2,500 subscribers and up to 15,000 emails a month with no credit card required. Unusually, automation, the API and the SMTP relay are all included on it. What is excluded is a dedicated IP, which starts on the Professional plan, and Sender branding on your emails is required at the free tier.
How much does Sender cost?
Standard is advertised at $7 a month, billed $84 for the first year, and Professional at $14 a month, billed $168 for the first year. Both figures are the defaults of a subscriber slider rather than fixed plan ceilings, so we do not publish a subscriber count against either price. Pay as you go is $5.80 per 1,000 emails. Enterprise is quoted individually.
What are the Sender SMTP settings?
The hostname is smtp.sender.net and the ports are 25, 2525 and 587. The vendor recommends 587 with TLS and names 2525 as the fallback when 587 is blocked. Authentication is PLAIN or LOGIN over TLS. There is no port 465. Your sending domain must be verified with SPF, DKIM and DMARC before the relay will accept mail, and no per-connection message limit is published.
Does Sender have an MCP server?
Yes, an official one, which puts it in a small group on this site. It runs at mcp.sender.net/mcp over Streamable HTTP with JSON-RPC 2.0, authenticates with an OAuth 2 bearer token scoped mcp:use, and exposes forty tools. Workflow creation is capped at 50 a day per account as, in the vendor documentation phrase, an agent-runaway backstop, and destructive operations require an explicit flag.
Can my account be banned on Sender?
Yes, and the policy is specific about it. Eight verticals are banned by name: affiliate marketing, gambling and betting, forex and get-rich-quick offers, pornography and dating, drugs and male enhancement, solo email ads, loans, and weight loss products. Spam complaints above 0.1 percent, any spamtrap hit, or a hard bounce rate above 10 percent lead to termination which the policy says happens without notice and with no refund. Three reviewers describe suspensions, one of them for cold B2B outreach to publicly available contacts.
Is Sender good for deliverability?
Nobody has measured it. Sender has never been included in a seedlist panel and has no page on the second panel we use, so there is no independent inbox placement figure of any kind. What can be said is structural: it requires SPF, DKIM and DMARC before you can send, enforces a 0.1 percent complaint ceiling and a 10 percent bounce ceiling, and offers a dedicated IP from the Professional plan. Those are the right practices, unverified by anyone outside the company.
Changelog
| Date | Change |
|---|---|
| 27 August 2026 | First publication. 50 of 211 Capterra rows read, 20 of 1,388 Trustpilot rows read, 0 of 274 G2 rows rendered and none quoted. The Trustpilot corpus was identified as a post-chat solicitation funnel from the sample read and is reported as such rather than blended with Capterra. Every SMTP port, price, quota and policy clause was confirmed on a second literal read of the same URL. Two Capterra sub-scores that did not reproduce on the second read were discarded. Sender was verified as absent from the EmailToolTester panel specifically so that no percentage from that page could be attached to it in error. The subscriber counts behind the $7 and $14 prices are slider defaults and are deliberately not published. |
This review follows our email infrastructure testing methodology. We disclose affiliate relationships in our editorial independence policy.
