CloudMailin vs EmailEngine

CloudMailin receives email and delivers it to web applications through HTTP POST webhooks. Inbound messages can arrive as JSON, multipart form data, or raw text; attachments can be forwarded to a webhook or stored in Amazon S3, Azure Storage, or Google Cloud Storage. It also sends transactional email through an API or SMTP relay. Outbound tools include spam checks, link and open tracking, bounce handling, reporting, tagging, and priority queues. Inbound delivery history includes 30 days of searchable records with error and retry details, while metadata retention is listed as 60 days. CloudMailin says its inbound service works with any language or framework, naming examples from Node.js and Python to Java and C#. The service was founded in 2010 and is available through an API and the web. A free plan allows 10,000 emails per month and 512KB per message. Paid plans start at $25 a month; the listed options include different email and message-size limits. A seven-day trial is also listed.

EmailEngine is a self-hosted email API that connects Gmail, Microsoft 365, and IMAP mailboxes through a unified REST API. It sends webhooks when mailbox messages or state change, and can send mail through the connected account’s SMTP server or provider API. Native integrations use the Gmail API and Microsoft Graph; authentication options include managed OAuth2, service accounts for Google Workspace, Microsoft 365 app-only access, and shared or delegated mailboxes. An optional MCP server, currently in beta, lets connected AI clients search, read, file, draft, and send email with approved access. The admin interface shows sync status and queue details, with a Prometheus endpoint and Grafana dashboard for operations. EmailEngine runs on the customer’s infrastructure, uses Redis for sync metadata, and fetches message bodies on demand rather than storing them. A server and Redis using the noeviction policy are required. The annual subscription is $1,450 a year, excluding VAT where applicable, and includes developer support; each installation can start a full-functionality 14-day trial without signup or a credit card.