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Sync Notify
ContactInstall on Shopify

Connect Twilio SendGrid SMTP.

Connect through SendGrid's SMTP relay with an API key. The username is always the literal word apikey, and TLS 1.2 or newer is required.

3 MIN READALL PLANSUPDATED OCT 2026

What you need.

01

An active Twilio SendGrid account

02

A verified Single Sender or authenticated sending domain

03

A SendGrid API key with Mail Send permission

04

A client and network that support TLS 1.2 or newer

Steps

  1. Verify the sending identitySign in to SendGrid. Verify the From address or authenticate the domain you will use.
  2. Create an API keyCreate an API key with Mail Send permission, then copy it. SendGrid only shows the full key once.
  3. Add the connection in Sync NotifyUse smtp.sendgrid.net on port 587 with TLS. Enter apikey as the username exactly, then paste the API key as the password.
  4. Test and sendRun Test and send with the verified From address. If your network blocks port 587, try port 2525 with TLS or port 465 with SSL.

Settings to enter.

Sync Notify fills these in when you choose the SendGrid preset. They are here so you can check them.

SENDGRID PRESET
SMTP host
smtp.sendgrid.netDo not hard-code a SendGrid IP address
Recommended port
587TLS
Alternative TLS ports
25 or 25252525 is useful when standard SMTP ports are blocked
SSL port
465Implicit SSL
Username
apikeyThe literal lowercase word, not the API key value
Password
SendGrid API keyRequires at least Mail Send permission
Provider limits
5,000 messages/SMTP connectionUp to 10,000 concurrent connections from one server; the account plan's sending allowance also applies

Common errors.

ERR 01535 Authentication failed

The username is not exactly apikey, the key is invalid, or it lacks Mail Send permission. Set the username to the literal word apikey and create a replacement API key with Mail Send access.

ERR 02The From address is rejected

The sender address or domain has not completed SendGrid sender authentication. Complete Single Sender Verification or Domain Authentication, then use that verified identity as the From address.

ERR 03TLS handshake or connection failure

The client is using TLS older than 1.2, or the network blocks the selected SMTP port. Use TLS 1.2 or newer on port 587. If 587 is blocked, try TLS on 2525 or SSL on 465.

Official references.