Connect Your Email Using SMTP (Single Account)

SMTP connection allows you to connect email accounts from providers that don't support OAuth authentication, or when you need more direct control over the connection method. This includes custom domain emails, private email servers, and providers like Yahoo, Zoho, GMX, and others.

This guide explains when SMTP connection is appropriate, what information you'll need, and how to complete the setup successfully.

When to Use SMTP Connection

SMTP is the right connection method when:

Your email provider doesn't offer OAuth authentication, such as Yahoo Mail, Zoho, or custom email servers
You're using a custom domain hosted on providers other than Google or Microsoft
You have specific server configurations that require manual SMTP settings
Your organization requires direct SMTP access for compliance or security reasons

If your email is hosted on Google Workspace or Microsoft 365,an OAuth connection is recommended over SMTP for better security and easier maintenance.

Understanding SMTP Authentication

SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending emails. When you connect via SMTP, you provide TrulyInbox with your email server details and login credentials so it can send emails on your behalf.

Unlike OAuth, SMTP connection requires:

Direct access to your email password or an app-specific password
Manual entry of server settings such as host address and port numbers
Ongoing credential management if passwords change

SMTP is reliable and widely supported, but it requires more initial setup than OAuth methods.

Required Information Before You Start

Before connecting via SMTP, gather the following information from your email provider:

SMTP Server Address (Host): The outgoing mail server address, typically something like smtp.yourprovider.com
SMTP Port: The port number used for sending emails, commonly 587 (TLS) or 465 (SSL)
Email Address: Your full email address
Password or App Password: Your email account password, or an app-specific password if your provider requires one
Encryption Method: Usually TLS or SSL

Most email providers list SMTP settings in their help documentation or account settings. If you're unsure, check your provider's support site or contact their support team.

How to Connect Your Email Using SMTP

Step 1: Navigate to Add Email Account

Step 2: Select SMTP Connection

From the available connection options, choose SMTP or Custom SMTP. This opens the manual configuration form.

Step 3: Fill in All Required Details

Enter the following information in the connection form:

Email Address: Your complete email address (e.g., [email protected])
SMTP Host: Your provider's SMTP server address (e.g., smtp.yourprovider.com)
SMTP Port: 587 for TLS or 465 for SSL
Encryption: Select TLS or SSL (most providers use TLS on port 587)
IMAP Server: Your provider's IMAP server address (e.g., imap.yourprovider.com)
IMAP Port: Usually 993
Password: Your email password or app-specific password
Important: If your email provider uses two-factor authentication, you must generate an app-specific password:
Log in to your email provider's security settings
Generate a new app password for TrulyInbox
Use that app password instead of your regular password

Step 4: Validate, Connect, and Save

Click "Test Connection" to verify your settings. If successful, click "Connect Save."

Common SMTP Connection Errors

Incorrect settings or provider-specific security requirements usually cause SMTP connection issues. Here are the most common errors and how to resolve them:

Authentication Failed

This error means the email address or password is incorrect, or the provider requires an app-specific password.

Solution: Verify your email and password are correct. If your provider uses two-factor authentication, generate an app password and use that instead of your regular password.

Connection Timeout or Refused

This indicates the SMTP server address or port is incorrect, or the provider is blocking the connection.

Solution: Double-check the SMTP host and port number against your provider's official documentation. Ensure you're using the correct encryption method (TLS vs SSL).

TLS/SSL Certificate Errors

This occurs when the encryption method doesn't match the port or server configuration.

Solution: Verify you're using TLS on port 587 or SSL on port 465 as required by your provider. Some providers only support one encryption method.

SMTP Not Enabled

Some email providers disable SMTP access by default or require you to enable it in account settings.

Solution: Log in to your email provider's settings and enable SMTP, POP, or IMAP access. Providers like Yahoo and Zoho often require this step before external applications can connect.

App Password Required

Many providers that support two-factor authentication require app-specific passwords for SMTP access.

Solution: Generate an app password from your email provider's security settings and use that password in TrulyInbox instead of your regular account password.

Final Notes

SMTP connection provides reliable access for email providers that don't support OAuth or when direct server access is needed. While setup requires more manual configuration than OAuth methods, SMTP remains the standard for connecting custom and alternative email providers.

Always use the most secure authentication method your provider offers, and keep credentials updated to maintain uninterrupted service.

If you encounter connection issues that persist after verifying settings, support is available to help troubleshoot provider-specific configurations.

Also check

Understanding Which Connection Method to Use And When

Technical Checklist Before Starting Email Warm-up

How to fix SMTP/IMAP "Could not authenticate" error?

My Email Account is Disconnected. What are the possible reasons?