Developer docs · InboxRatio Editorial
MailUp email API: SDKs, docs and limits (2026)
Every link below points into MailUp's official developer documentation and was checked on 10 September 2026. We record only what the vendor documents — a field we could not verify at the source is left out, never guessed.
From MailUp's official docs · checked 10 September 2026
Docs, SDKs and limits
- SMTP relay
- Yes — SMTP+ service · SMTP docs
From our feature matrix — documented by the vendor
API, SMTP and sending auth
- API'External database, CRM, CMS, ERP, e-commerce and business intelligence systems. Integrate your system' — API not named on fetched pages
- SDKs / client librariesReleased .NET SDK (NuGet MailUp.Sdk) and Ruby wrappers (mailup-ruby, omniauth-mailup); REST demo-client samples in VB.NET, C#, PHP, Java, Objective-C, JavaScript
- Public API docsPublic MailUp API docs (REST, SOAP, HTTPS Get/Post, SMTP relay, FTP); linked from features page as help.mailup.com/display/mailupapi/
- Webhooks'Webhooks allow you to communicate to another application that something happened in your MailUp account'; retries over a 25-hour period; configured under Developer's Corner
- SMTP API'Send transactional messages with SMTP+, MailUp's built-in high deliverability SMTP relay service, or the MailUp API'
- SMTP relaySMTP+ built-in SMTP relay (credentials under Settings > List settings > SMTP+); tracks opens/clicks and manages bounces and feedback loops automatically
- Transactional emailSMTP+ relay lets you 'send transactional emails in a high-deliverability, high-capacity environment'; 'included at no additional cost with every MailUp account'
- SPF assistance'MailUp lets you easily customize your email authentication with your domain' — SPF not named
- DKIM setupDomain authentication customization documented; DKIM not named on fetched page
- DMARC supportDeliverability Checkup flags 'your domain does not have a DMARC record' and gives a p=none observation-mode TXT record to publish
Features checked 10 September 2026. ✓ documented · ◐ limited or plan-gated · × documented as absent · — not documented. Documentation is not a measured result — see our methodology.
Generated from our datasets — every value verified and dated
Frequently asked questions
Where are the official MailUp API docs?
MailUp's official developer documentation is at https://helpmailup.atlassian.net/wiki/spaces/mailupapi/pages/36342258/REST+API. Links checked on 10 September 2026.
Does MailUp support SMTP relay?
Yes. MailUp's official docs document SMTP relay sending (SMTP+ service): https://helpmailup.atlassian.net/wiki/spaces/mailupapi/pages/36340677/SMTP+relay+service (checked 10 September 2026).