Email Setup (SendGrid)

1. Go to SendGrid Dashboard → Settings → API Keys
2. Click Create API Key
3. Name it something like Nero Integration
4. Select Full Access (or at minimum: Mail Send + Inbound Parse)
5. Click Create & View: copy the key immediately (you won't see it again)

1. Go to Settings → Sender Authentication
2. Choose Single Sender Verification (quickest) or Domain Authentication (recommended for production)
3. For Single Sender: enter the email you want to send from (e.g. support@yourcompany.com) and verify via the confirmation email
4. For Domain Authentication: follow SendGrid's DNS instructions to add CNAME records

1. Open Nero → Settings → Integrations
2. Click Connect on the SendGrid card
3. Enter:
   • API Key: paste the key from Step 1
   • Sender Email: the verified email from Step 2
   • Sender Name: how your name appears to recipients (e.g. Your Company)
   • Region: select your SendGrid region (see below)
4. Click Save & Connect: Nero validates your key and sends a test email automatically

Region selection

SendGrid has two data regions: Global (US) and Europe (EU).

How to determine your region:

• If your SendGrid dashboard URL is app.sendgrid.com → you're on Global (US)
• If your SendGrid dashboard URL is app.eu.sendgrid.com → you're on Europe (EU)

Important: You must select the correct region in Nero. Selecting the wrong region will result in a "User is not authorized to send mail based on their regional attribute" error. Free and Essentials plans do not support EU Data Residency. Only Pro plans and above support it. If you're on a free or Essentials plan, select Global (US).

1. After connecting, click Send Test on the SendGrid card
2. Enter a recipient email address (e.g. your own email)
3. Check your inbox: you should receive a test email from Nero

To receive email replies in Nero, use a subdomain so your existing email (Google Workspace, Outlook, etc.) is not affected.

5a. DNS: MX record for subdomain

Add an MX record for a subdomain (e.g. nero.yourcompany.com) at your DNS provider:

Type:     MX
Host:     nero (creates nero.yourcompany.com)
Value:    mx.sendgrid.net
Priority: 10

Important: Do NOT set MX on @ (your root domain), as that would break your existing email. Always use a subdomain like nero, mail, or inbound.

5b. SendGrid: Inbound Parse

1. In SendGrid Dashboard → Settings → Inbound Parse
2. Click Add Host & URL
3. Fill in:
   • Receiving Domain: nero.yourcompany.com (your subdomain)
   • Destination URL: https://nerops.ai/api/webhooks/sendgrid?token=YOUR_WEBHOOK_TOKEN
   • Leave "POST the raw, full MIME message" unchecked
4. Click Add

Security: The token query parameter authenticates webhook requests. Your webhook token is provided by your Nero administrator. This prevents unauthorized parties from injecting fake emails into your workspace.

5c. Nero: set inbound domain

1. Go to Settings → Integrations → SendGrid
2. Fill in Inbound Domain: nero.yourcompany.com
3. Save

5d. Google Workspace: forward replies to Nero

Set up a routing rule so replies to your team arrive in both Gmail and Nero:

1. Open Google Workspace Admin Console → Apps → Google Workspace → Gmail → Routing
2. Click Configure (or Add another rule)
3. Fill in:
   • Description: Forward to Nero
   • Email messages to affect: Inbound
   • Action: select Also deliver to → enter inbound@nero.yourcompany.com
4. Click Save

Now when a client replies to lisa@yourcompany.com:

• The reply arrives in Lisa's Gmail as normal
• Google Workspace forwards a copy to inbound@nero.yourcompany.com
• SendGrid Inbound Parse routes it to Nero
• Nero creates a message and triggers AI triage

How Reply-To routing works

All outgoing emails from Nero automatically set a Reply-To header pointing to your inbound domain. This ensures replies come back into Nero without the customer noticing anything different.

The From stays the real email address, so the customer sees a recognizable sender. The Reply-To redirect is invisible in most email clients.

Email threading

Nero maintains email threads using standard headers:

• Message-ID: unique ID per sent email
• In-Reply-To: references the message being replied to
• References: chain of all messages in the thread

This ensures replies are neatly grouped in the same thread in Gmail, Outlook, and other email clients.

Contact matching

When an email arrives in Nero:

1. Existing contact? Nero searches by email address in your contacts
2. Found? The message is linked to the existing contact
3. New? A new contact is automatically created with name and email from the email headers

Emails from your own team members are recognized automatically. If the sender has a profile with a matching sender_email, the message is marked as internal.