Sub-processors
Last updated: 5 October 2026
PlainMailOS uses the service providers below to run the Service. Each is bound by a contract that limits its use of customer data to providing its service to us. We will update this page before adding a new sub-processor that handles customer personal data; customers under our Data Processing Addendum can ask to be notified by email.
Railway Corp.
Purpose: Hosting: application servers, database, job queue and database backups
Data: All data stored in the Service
Location: United States
Paddle.com Market Ltd
Purpose: Payments and subscriptions (merchant of record), including Paddle Retain for billing reminders
Data: Billing contact, plan and seat count; card details are collected by Paddle directly
Location: United Kingdom, with processing in other countries
Resend, Inc.
Purpose: Transactional email (verification, password reset, invitations, notices) and delivery of contact-form messages to us
Data: Recipient email address and the content of those emails
Location: United States
OpenAI, L.L.C.
Purpose: AI assistance for classification, only for organizations that turn it on
Data: Message subject, sender name and domain, and up to about 6,000 characters of body text
Location: United States
Functional Software, Inc. (Sentry)
Purpose: Error reporting, only when enabled
Data: Scrubbed error details (no message content, credentials or email addresses)
Location: United States
Mail providers you connect
Google (Gmail), Microsoft (Outlook and Microsoft 365) and IMAP providers are not our sub-processors: they are your providers, and PlainMailOS connects to them on your instruction to read your mailboxes.