SMTP Setup

Each project requires SMTP configuration to send emails. SendDock connects to your SMTP server directly.

Configuration

Go to SMTP Settings in the project sidebar and fill in:

Field	Description	Example
SMTP Host	Your SMTP server hostname	smtp.gmail.com
Port	SMTP port (usually 587 for TLS)	587
Username	SMTP authentication username	you@gmail.com
Password	SMTP password or app-specific password	xxxx xxxx xxxx xxxx
From Name	Display name for the sender (optional)	My Newsletter
From Email	Email shown as sender (optional, defaults to username)	noreply@mydomain.com

Testing

After saving, click Test Connection. SendDock will send a test email to the configured from address (or SMTP username) to verify the connection works.

Why your local install times out

Most residential ISPs (Comcast, Claro, Movistar, BT, and many more) block outbound TCP ports 25, 465 and 587 at the network edge to prevent spam botnets. This means a SendDock instance running on your laptop or home server cannot reach external SMTP providers at all — it has nothing to do with SendDock or your credentials. You will see a 10-second timeout error.

There are three ways around it:

1. Run SendDock on a public domain / cloud server. Cloud providers (DigitalOcean, Hetzner, AWS, etc.) do not apply the residential SMTP block. This is the supported production setup. See Installation.
2. Use port 2525 if your provider supports it. SendGrid, Mailgun, Postmark, Resend and Brevo all listen on 2525 specifically as an escape hatch for ISP-blocked users. Self-hosted Mailcow / Postfix / Stalwart instances can be configured the same way.
3. For local development, use a fake SMTP catcher like Mailpit — it accepts any auth on localhost:1025 and shows captured emails in a web UI. SendDock ships a mail profile in its dev docker-compose.yml for exactly this case.

Common SMTP Providers

Gmail

• Host: smtp.gmail.com
• Port: 587
• Username: your Gmail address
• Password: App Password (not your regular password)

Amazon SES

• Host: email-smtp.{region}.amazonaws.com
• Port: 587
• Username: SES SMTP username (from IAM)
• Password: SES SMTP password (from IAM)

Mailgun

• Host: smtp.mailgun.org
• Port: 587
• Username: your Mailgun SMTP username
• Password: your Mailgun SMTP password

Resend

• Host: smtp.resend.com
• Port: 465
• Username: resend
• Password: your Resend API key

Custom / Self-hosted (Postfix, etc.)

• Host: your server's hostname or IP
• Port: 25, 465, or 587
• Username/Password: as configured on your server

From Email vs SMTP Username

The SMTP username is used for authentication. The From Email is what recipients see as the sender address. These can be different if your SMTP provider allows it (e.g., sending from noreply@yourdomain.com while authenticating with smtp-user@provider.com).

If From Email is not set, the SMTP username is used as the sender address.