Connect Multiple Email Accounts Using SMTP (Bulk Setup)

Hey Users,

Need to connect multiple email accounts at once? Bulk SMTP setup lets you add dozens—or even hundreds- of email accounts in one go, saving you tons of time.

Bulk SMTP connection is designed for teams, agencies, and power users who need to connect many email accounts quickly. Instead of adding accounts one by one, you can upload all your email credentials and server settings in a single file.

This guide explains how bulk uploads work, the format to use, and best practices to ensure all accounts connect successfully on the first try.

When to Use Bulk SMTP Setup

Bulk SMTP connection is ideal when:

• You're onboarding an entire team and need to connect multiple accounts at once

• You're an agency managing email warmup for multiple clients

• You're migrating from another platform and have many accounts to reconnect

• You want to save time by avoiding repetitive manual entry

For connecting just one or two accounts, single-account setup is simpler and faster.

What You'll Need Before Starting

Before uploading accounts in bulk, gather the following information for each email account:

• Complete email address

• SMTP server address

• SMTP port number (587 or 465)

• IMAP server address

• IMAP port number (usually 993)

• Email password or app-specific password

Having all this information ready before you start will make the bulk upload process smooth and error-free.

Bulk Upload Format

TrulyInbox accepts bulk email uploads in CSV (Comma-Separated Values) format. Your CSV file must include specific columns in the exact order shown below.

Required CSV Columns

Your CSV file must contain the following columns:

1. email - The complete email address

2. smtp_host - SMTP server address (e.g., smtp.provider.com)

3. smtp_port - SMTP port number (587 or 465)

4. smtp_username - Usually the same as email address

5. smtp_password - Email password or app-specific password

6. imap_host - IMAP server address (e.g., imap.provider.com)

7. imap_port - IMAP port number (usually 993)

8. imap_username - Usually the same as email address

9. imap_password - Usually the same as SMTP password

How to Connect Multiple Accounts Using Bulk SMTP

Step 1: Prepare Your CSV File

Create a CSV file using Excel, Google Sheets, or any text editor. Make sure all required columns are included in the correct order with accurate information for each account.

Pro tip: Start with a small test file (3-5 accounts) to verify your format is correct before uploading your full list.

Step 2: Navigate to Bulk Upload

Log in to your TrulyInbox account and click the "Add Email Account" button.

Select "SMTP/IMAP Account" and then choose "Bulk Upload."

Step 3: Upload Your CSV File

Click "Choose File" or "Upload CSV" and select your prepared CSV file from your computer.

TrulyInbox will immediately validate the file format and check for common errors.

Step 4: Review Validation Results

Click "Choose File" or "Upload CSV" and select your prepared CSV file from your computer.

Once you upload the file, TrulyInbox will process all accounts, and they will immediately reflect in your account list.

Step 5: Download Your Status Reports

After upload completes, you'll receive two downloadable reports:

Status Report - Shows the complete upload summary:

• Total accounts processed

• Successfully connected accounts

• Failed accounts

• Connection status for each email

Error Report (if applicable) - Details exactly what went wrong:

• Which accounts failed to connect

• Specific error messages for each failure

• What needs to be fixed (e.g., "Invalid SMTP port" or "Authentication failed")

Download both reports to keep a record of your bulk upload and to identify any accounts that need attention.

Step 6: Fix Any Failed Connections

If the error report shows failed accounts:

• Review the error details - The report clearly explains what needs to be fixed for each failed account

• Edit your CSV file - Correct only the accounts that failed

• Re-upload the corrected file - Successfully connected accounts won't be affected; only the fixed accounts will be processed

Common errors include:

• Incorrect passwords or missing app-specific passwords

• Wrong SMTP/IMAP server addresses

• Invalid port numbers

• Missing required fields

Step 7: Verify All Accounts Are Connected

Check your email account list to confirm all accounts appear and show as "Connected" status.

Validation Rules and Requirements

To ensure successful bulk uploads, the system enforces these validation rules:

File Format Rules

• File must be in CSV format (.csv extension)

• First row must contain column headers exactly as specified

• No empty rows between data entries

• Maximum file size: 10MB

• Maximum accounts per upload: 500 (contact support for larger uploads)

Email Address Rules

• Must be a valid email format ([email protected])

• No duplicate email addresses in the same upload

• No spaces before or after the email address

Server Settings Rules

• SMTP port must be 25, 465, 587, or 2525

• IMAP port must be 143 or 993

• Server addresses must be valid hostnames (no http:// or https://)

• Encryption is automatically determined based on port number

Password Rules

• Cannot be empty

• Special characters are allowed

• No minimum or maximum length

• App-specific passwords strongly recommended for accounts with 2FA

Best Practices for Bulk Connections

Follow these best practices to ensure smooth bulk uploads:

Before Upload

• Test with a small batch first - Upload 3-5 accounts to verify your format is correct before uploading hundreds

• Use app-specific passwords - For accounts with two-factor authentication, always generate app passwords

• Verify server settings - Double-check SMTP/IMAP addresses and ports for each provider

• Remove duplicates - Ensure no email address appears multiple times in your file

• Keep a backup - Save a copy of your CSV file before uploading, in case you need to make corrections

Common Bulk Upload Errors and Solutions

CSV Format Errors

Error: "Invalid CSV format" or "Missing required columns."

Solution: Verify your CSV has all required column headers in the exact order specified. Use the sample format provided above.

Authentication Failures

Error: "Authentication failed" for specific accounts

Solution: Check that passwords are correct and that app-specific passwords are being used for accounts with 2FA enabled.

Server Connection Errors

Error: "Cannot connect to server" or "Connection timeout"

Solution: Verify SMTP/IMAP server addresses are correct and that port numbers match your provider's requirements.

Duplicate Email Addresses

Error: "Email address already exists"

Solution: Remove duplicate entries from your CSV file. Each email can only be connected once.

Invalid Port Numbers

Error: "Invalid SMTP/IMAP port"

Solution: Use standard port numbers: 587 or 465 for SMTP, 993 or 143 for IMAP.

Handling Partially Successful Uploads

If some accounts connect successfully while others fail:

• Successfully connected accounts remain active - No need to reconnect them

• Failed accounts can be fixed individually - Either edit and re-upload just the failed accounts, or add them manually one by one

• Download the error report - This shows exactly which accounts failed and why

You can re-upload only the failed accounts after fixing the errors without affecting already-connected accounts.

Security Considerations for Bulk Uploads

When uploading multiple accounts:

• Protect your CSV file - It contains sensitive credentials and should be stored securely

• Delete after upload - Remove the CSV file from your computer once accounts are connected

• Use secure connections - Always upload from a secure, trusted network

• Audit regularly - Review connected accounts periodically and remove any that are no longer needed

• Enable 2FA - Use app-specific passwords for accounts with two-factor authentication enabled

What Happens After Bulk Connection

Once accounts are connected:

• All accounts appear in your email list - You can manage them individually or in bulk

• Warmup can be configured - Apply warmup settings to individual accounts or all at once

• Connection status is monitored - You'll be notified if any connection issues occur

• Settings can be updated - Change passwords or server settings anytime without re-uploading

Bulk Warmup Configuration

After connecting multiple accounts, you can apply warmup settings in bulk:

• Select multiple accounts from your list

• Choose "Edit Warmup Settings"

• Configure settings once and apply to all selected accounts

This saves even more time when managing large numbers of accounts.

Final Notes

Bulk SMTP connection is a powerful time-saver for teams and agencies managing multiple email accounts. By following the correct CSV format and validation rules, you can connect dozens or hundreds of accounts quickly and reliably.

Always start with a small test batch, use app-specific passwords where needed, and keep your credential files secure.

Need help? If you encounter issues with bulk uploads, reach out to support. We're happy to review your CSV format or troubleshoot connection problems!

Also check

Connect Your Email Using SMTP (Single Account)

Technical Checklist Before Starting Email Warm-up

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

Warmup Configuration