ERPNext ships with a built-in Email Domain / Email Account setup that speaks plain SMTP, and for low volume it works. The trouble starts as you scale: invoices, payment reminders, quotations, password resets, portal notifications and Notification/Auto Email Report messages all leave your instance over a single SMTP connection with no delivery telemetry. When mail bounces or a recipient marks it as spam, ERPNext never hears about it — the address stays in your Customer/Contact records, your sending reputation quietly degrades, and one day a whole domain's mail lands in Junk with no signal as to why. Native ERPNext has no concept of a bounce webhook, a complaint feedback loop, a suppression list, or per-domain deliverability metrics. That is exactly where teams outgrow the core.

This connector is a purpose-built Frappe app (its own module, DocTypes and hooks.py) that inserts a deliverability layer between ERPNext and modern transactional providers. It ships pluggable adapters for Resend, Amazon SES and Postmark (SendGrid optional), selected through a Transactional Email Settings single DocType where you store API keys in encrypted fields and pick the active provider per sending domain. Outbound mail is intercepted via ERPNext's Email Queue / make sending path so existing Notification, print-format and workflow emails route through the provider's API — no rewrite of your business logic. Every send is written to a Transactional Email Log DocType carrying the provider message ID, domain, recipient, status and timestamps, giving you an auditable trail keyed back to the originating document.

The inbound half is where the real value sits. We expose whitelisted, signature-verified webhook endpoints (via @frappe.whitelist(allow_guest=True)) that receive delivery, bounce, complaint and open events from your provider, verify the payload signature (SES SNS confirmation, Postmark/Resend HMAC), and update the matching log record. Hard bounces and spam complaints are automatically written to an Email Suppression DocType; a hooks.py doc event and a pre-send check then block future sends to suppressed addresses so you stop hammering dead mailboxes. Scheduler events reconcile provider stats and roll up Per-Domain Sending Stats (sent, delivered, bounced, complained, bounce-rate) that you can surface on a dashboard or pull through the Frappe REST API. We also hand you a documented DKIM/SPF/DMARC record set per domain and, where the provider API allows, verify domain/DKIM status from within ERPNext.

Because this is build-to-order, nothing is downloaded and flipped on. It begins with a scoping call to confirm your provider(s), sending domains, ERPNext version (v15 or v16), current volume and which document flows must be covered. ECOSIRE then builds your version of the app, validates it on a staging copy of your site through UAT, and installs it on production with a rollback plan. Typical delivery is one working week from confirmed scope depending on how many providers and domains you need. You receive the full source in a git repository, install and configuration on your bench, technical and user documentation, a training session and a post-go-live support window — you own the code outright.