If a SendGrid submission fails with write ECONNRESET, wait 2–3 minutes and resubmit the deal.
This error means the SMTP server closed the connection unexpectedly. It is often transient during bulk sending.
What causes write ECONNRESET
The connection can drop when any of these happen:
The SMTP server terminates the connection unexpectedly, often when sending multiple emails in bulk.
Connection pooling limits are exceeded. SendGrid allows 100 messages per SMTP connection.
Transient network issues, firewall settings, or temporary SMTP server problems interrupt the session.
Large bulk sends (500+ emails) run without enough connection management, so the server drops the connection.
Fix
Wait 2–3 minutes.
Resubmit the deal from MCA Pilot.
If the error continues after a successful Send test email or Test Connection, re-check the SendGrid sender fields and domain authentication in Reconnect your email sender. For first-time setup, see How to Set Up A Sendgrid Account.