Workspace data
Subscribers, campaign content, editable templates and reports are managed through SendMailOS, including when you choose your own sending server.
Explore the platformKnow the service boundary
Security and data flow
Understand what stays in SendMailOS when you use hosted delivery or connect your own sending server. Review credentials, replies and operating boundaries.
Understand where your email goes
Own-server delivery changes the outbound transport. It does not move the whole SendMailOS workspace onto your VPS.
Your team or applicationCreate a campaign or an API message
SendMailOS workspaceContacts · templates · campaigns · processing · reports
Hosted deliverySendMailOS sending infrastructure
Uses your hosted allowance
Uses your hosted allowance
Your server + IPYour connected VPS sends the email
VPS is billed separately
VPS is billed separately
Recipient mailbox providerApplies its own acceptance, spam and inbox rules
Your workspace, sending route and replies
Outbound sending
Hosted sends use the hosted allowance. Own-server sends use the connected server and its IP. Warm-up, server capacity, fair use and plan limits still apply.
Read the server guideReply conversations
Supported reply capture routes future replies to SendMailOS receiving and conversation storage. Inbox is designed for these conversations rather than as a general IMAP mailbox.
Understand InboxUse credentials with a clear scope
Server-side API keys
Create keys with the scopes your application needs. Store live keys on your backend or in a secret manager. Use dashboard-issued test keys for simulated sends.
Authentication guideUser-approved connections
Template Studio MCP connects through OAuth. You approve organizations and permissions on SendMailOS and can revoke access in Connected Apps.
Connect Template StudioVerify webhook events before using them
Check signatures against the original request body and handle repeated events using their IDs. A successful setup verification confirms that test request; it does not guarantee future endpoint availability.
Review the boundaries before rollout
Your VPS needs ongoing care
Choose a provider that permits your sending use case. Confirm outbound connectivity, DNS, reverse DNS and a suitable public IP. You remain responsible for your server provider and operating the VPS.
VPS checklistHandle received files cautiously
Incoming attachments are downloadable files and are not scanned for malware. Do not assume that the sender or an attachment is safe because a message appears in Inbox.
Reply capture detailsThis page explains current product boundaries. It is not a certification, audit attestation or a replacement for the service’s contractual documents.
Questions, answered
Does using my own server self-host the whole application?
No. Your connected server provides an outbound sending route. Campaigns, contacts, templates and reports remain managed in SendMailOS. Reply capture uses SendMailOS receiving and conversation storage.
Do own-server emails use hosted credits?
Emails actually delivered through your connected server do not use hosted credits. Hosted delivery uses the monthly hosted allowance. Your selected domain settings control routing; review the route before sending.
Should I give an AI assistant my API key?
No. Template Studio MCP uses an OAuth approval flow. Sign in on SendMailOS, choose the organizations and permissions, and manage the connection in Connected Apps. Keep API keys and passwords out of chat.
Are incoming attachments scanned for malware?
No. Treat incoming attachments as untrusted files. Inbox attachment downloads require authorized access, but the current reply-inbox documentation does not provide malware scanning.