Posta vs turboSMTP
Posta
goposta.devturboSMTP
turbosmtp.comSide by side
| Figure | Posta | turboSMTP |
|---|---|---|
| Price from | Free | €14.95/mo |
| Free plan | Yes | Yes |
| Free trial | — | Yes |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 18 |
| Spec score · Transactional Email Software | 7.9 (#25) | 8.7 (#8) |
| Spec score · Transactional email services | 8.0 (#26) | 9.1 (#3) |
| Spec score · Email APIs | 7.7 (#21) | 8.7 (#3) |
| Integrations | The maker lists official SDKs for Go, PHP, Java, and .NET, plus Prometheus integration and OAuth/SSO providers including Google, Keycloak, and authentik. | A Zapier app launched with Send Email and Find Email Status actions for connecting CRMs, forms, spreadsheets and other Zapier applications. |
| Security | Listed security features include hashed API keys, optional key expiration and IP allowlists, JWT authentication, role-based access, two-factor authentication, rate limiting, and session management. | Pricing lists SPF/DKIM authentication, API keys, custom sending domains with SPF/DKIM/DMARC, and two-factor authentication as security and compliance features. |
| Webhooks | Webhooks support event filters, HMAC signing, retries, and delivery tracking. | HTTPS webhooks report delivery events such as delivered, deferred, bounced and dropped, plus opens, clicks, unsubscribes and spam reports. |
| What it does | Posta is a self-hosted email delivery platform for sending and receiving email through an HTTP API. | turboSMTP provides hosted SMTP relay and API infrastructure for transactional, marketing and newsletter email delivery. |
Plans
turboSMTP
- FreeFree
- Basic€14.95 a month
- Pro€79.95 a month
- Silver€49 a month
- Gold€92 a month
- Resell€270 a month
- Titanium€450 a month
- Diamond€790 a month
- FREEFree
- BASIC€14.95 a month
In their own words
Posta
Posta is a free, AGPL-3.0 self-hosted platform for sending and receiving email through an HTTP API. It supports API sending, SMTP relay, inbound mail, and website form submissions. The REST API handles transactional, batch, and templated messages with attachments, scheduling, retries, and priority queues. Incoming mail can arrive through built-in SMTP with TLS or an authenticated webhook, with forwarding and real-time SSE notifications. Templates offer versioning, localization, visual editing, and preview; campaigns add scheduling, A/B testing, and send-rate throttling. Posta supports multiple SMTP providers, SPF, DKIM, and DMARC verification, plus SDKs for Go, PHP, Java, and .NET. Security controls include hashed API keys, optional expiration and IP allowlists, JWT authentication, roles, two-factor authentication, rate limiting, and session management. It runs on customer infrastructure, with Docker Compose startup, isolated workspaces, data import/export, and GDPR deletion tools.
turboSMTP
turboSMTP is a cloud SMTP service for sending email messages and newsletters, with statistical analysis for individual and aggregate messages. Its SMTP API supports transactional messages such as login confirmations, welcome messages, and receipts from a website or app. The dashboard tracks clicks and opens in real time, while listed tools manage bounces, spam, and unsubscribes. Deliverability features include smart routing, custom tracking domains, and email validation before campaigns. An email marketing tool can design, send, and track campaigns using turboSMTP delivery infrastructure. The service lists SMTP relay, email templates, delivery event webhooks, and a dedicated IP option; inbound email is not supported. It offers a free plan allowing 200 emails per day for the first six months. Basic costs €14.95 a month for 15,000 emails per month; Pro costs €79.95 a month for the same send limit and up to 100 subaccounts. Other listed plans sell email credits, which expire one year after purchase. Platforms include Android, API, iOS, and web. The maker advertises 24/7 multilingual support by phone, chat, and email.