SMTP Email Sender

Prerequisites

1. Gmail Users

1. Enable two-step verification
2. Create an App Password
   • Visit: https://myaccount.google.com/apppasswords
   • Select "Mail" and the app name
   • Copy the generated 16-digit password

2. Outlook/Hotmail Users

1. Enable two-step verification
2. Create an app password: https://account.microsoft.com/security
3. Or use your regular password (if allowed)

3. Corporate Mailbox Users

• SMTP server address
• SMTP port (usually 587 or 465)
• Whether SSL/TLS is required

Configuration

.env

# SMTP Configuration
SMTP_SERVER=smtp.gmail.com
SMTP_PORT=587
SMTP_USERNAME=your_email@gmail.com
SMTP_PASSWORD=your_app_password  # Use App Password for Gmail
SMTP_USE_TLS=true

Usage

Basic Usage

send_email.py

python scripts/send_email.py \
  --to recipient@example.com \
  --subject "Email Subject" \
  --body "Email Content"

Full Parameters

--to

--subject

--body

--cc

--bcc

--attachment

--is_html

--from_name

Examples

python scripts/send_email.py \
  --to friend@example.com \
  --subject "Weekend Gathering" \
  --body "Are you free this weekend? Let's have dinner together!"

python scripts/send_email.py \
  --to boss@company.com \
  --subject "Project Report" \
  --body "<h1>Project Progress Report</h1><p>Please see attachments for details...</p>" \
  --is_html true \
  --attachment "report.pdf,chart.xlsx" \
  --from_name "Zhang San"

python scripts/send_email.py \
  --to "alice@example.com,bob@example.com" \
  --cc "manager@example.com" \
  --subject "Meeting Minutes" \
  --body "Below are the minutes from today's meeting..."

Supported SMTP Configurations

Gmail

SMTP_SERVER=smtp.gmail.com
SMTP_PORT=587
SMTP_USE_TLS=true

Outlook/Hotmail

SMTP_SERVER=smtp-mail.outlook.com
SMTP_PORT=587
SMTP_USE_TLS=true

QQ Mail

SMTP_SERVER=smtp.qq.com
SMTP_PORT=587
SMTP_USE_TLS=true

163 Mail

SMTP_SERVER=smtp.163.com
SMTP_PORT=587
SMTP_USE_TLS=true

Corporate Mailbox (Example)

SMTP_SERVER=smtp.company.com
SMTP_PORT=587
SMTP_USE_TLS=true

FAQs

1. Authentication Failure

• Ensure two-step verification is enabled
• Use the App Password, not your regular password
• Check if "Less secure app access" is enabled (not recommended)

• Check if an app password is required
• Confirm the SMTP address is correct

2. Connection Timeout

• Check firewall settings
• Try port 465 (SSL) instead of 587 (TLS)
• Confirm the SMTP server address is correct

3. Attachment Too Large

• Gmail limits attachments to 25MB
• Outlook limits attachments to 20MB
• For large files, it's recommended to use cloud storage links

Security Recommendations

1. Never hardcode passwords in your code
2. Use environment variables or encrypted configuration files
3. Regularly update your App Password
4. Do not send sensitive information via SMTP on public networks

Troubleshooting

python scripts/test_smtp.py

1. Whether the configuration in the

   .env

   file is correct
2. Whether the network connection is normal
3. Whether the email account and password are correct
4. Whether the firewall blocks the SMTP port