Email Server Setup Script

This script automatically sets up a complete email server with the following components:

• Postfix - SMTP server for sending/receiving emails
• Dovecot - IMAP/POP3 server for email retrieval
• PostgreSQL - Database backend for virtual domains and users
• PostfixAdmin - Web interface for managing domains and mailboxes
• Amavis - Content filter for spam and virus scanning
• SpamAssassin - Spam filtering
• ClamAV - Antivirus scanning
• OpenDKIM - DKIM signing for email authentication
• Let's Encrypt - SSL/TLS certificates for secure connections

Prerequisites

1. Fresh Ubuntu/Debian server (tested on Ubuntu 20.04/22.04)
2. Root access to the server
3. Domain name pointing to your server
4. Hostname (e.g., mail.yourdomain.com) with A record pointing to server IP
5. Ports 25, 587, 465, 110, 995, 143, 993, 80, 443 open in firewall

DNS Prerequisites

Before running the script, ensure you have these DNS records:

A     mail.yourdomain.com    [Your Server IP]
MX    yourdomain.com         mail.yourdomain.com

Installation

1. Download the script:

   wget https://raw.githubusercontent.com/your-repo/setup-email-server.sh
   chmod +x setup-email-server.sh
   

2. Run the script as root:

   sudo ./setup-email-server.sh
   

3. Provide the required information when prompted:

   • Domain name (e.g., yourdomain.com)
   • Hostname (e.g., mail.yourdomain.com)
   • Admin email address
   • PostgreSQL password for postfix user
   • PostfixAdmin setup password

Post-Installation Steps

1. Add DNS Records

After the script completes, add these DNS records:

SPF Record

TXT   yourdomain.com   "v=spf1 mx ~all"

DMARC Record

TXT   _dmarc.yourdomain.com   "v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com"

DKIM Record

The script will display the DKIM DNS record. Add it to your DNS:

TXT   mail._domainkey.yourdomain.com   "v=DKIM1; k=rsa; p=..."

2. Complete PostfixAdmin Setup

1. Visit https://mail.yourdomain.com/postfixadmin/setup.php
2. Enter the setup password you provided during installation
3. Create an admin user
4. Login to PostfixAdmin at https://mail.yourdomain.com/postfixadmin/

3. Create Domains and Mailboxes

1. Add your domain in PostfixAdmin
2. Create mailboxes for your users
3. Test email functionality

Multiple Domain Support

This email server fully supports unlimited virtual domains. Each domain can have its own mailboxes, aliases, quotas, and DKIM signing.

Adding Additional Domains

Method 1: Using the Helper Script (Recommended)

# Add DKIM support for a new domain
sudo ./add-domain.sh newdomain.com

# This will:
# - Generate DKIM keys
# - Update OpenDKIM configuration  
# - Display DNS records to add
# - Show PostfixAdmin setup instructions

Method 2: Manual Process

1. Add domain via PostfixAdmin:

   • Login to PostfixAdmin
   • Go to "Domain List" → "New Domain"
   • Enter domain details and save

2. Configure DKIM for the domain:

   sudo ./add-domain.sh newdomain.com
   

3. Add DNS records for the new domain:

   MX    newdomain.com       mail.yourmainhost.com
   TXT   newdomain.com       "v=spf1 mx ~all"
   TXT   _dmarc.newdomain.com "v=DMARC1; p=none; rua=mailto:dmarc@newdomain.com"
   TXT   mail._domainkey.newdomain.com "v=DKIM1; k=rsa; p=..."
   

Managing Multiple Domains

Use the domain management script for comprehensive domain operations:

# List all configured domains
sudo ./manage-domains.sh list

# Show detailed information for a domain
sudo ./manage-domains.sh show example.com

# Test domain configuration (DNS, DKIM, etc.)
sudo ./manage-domains.sh test example.com

# Add a new domain
sudo ./manage-domains.sh add newdomain.com

# Remove a domain (WARNING: deletes all data)
sudo ./manage-domains.sh remove olddomain.com

# Show overall server status
sudo ./manage-domains.sh status

Application SMTP for Multiple Domains

Applications can send from any configured domain using the same SMTP server:

# Example: Send from different domains
domains = ['company.com', 'mysite.org', 'shop.net']

for domain in domains:
    smtp_config = {
        'host': 'mail.yourmainhost.com',
        'port': 587,
        'username': f'noreply@{domain}',
        'password': 'domain_specific_password'
    }
    # Send email using this configuration

Security Features

• SSL/TLS encryption for all connections
• DKIM signing for email authentication
• SPF and DMARC policies for anti-spoofing
• Spam filtering with SpamAssassin
• Virus scanning with ClamAV
• Secure authentication with encrypted passwords
• Firewall rules restricting access to necessary ports

Email Ports

• 25 - SMTP (incoming mail)
• 587 - Submission (authenticated sending)
• 465 - SMTPS (secure SMTP)
• 143 - IMAP
• 993 - IMAPS (secure IMAP)
• 110 - POP3
• 995 - POP3S (secure POP3)

Client Configuration

IMAP Settings

• Server: mail.yourdomain.com
• Port: 993 (SSL) or 143 (STARTTLS)
• Security: SSL/TLS
• Authentication: Normal password

SMTP Settings

• Server: mail.yourdomain.com
• Port: 587 (STARTTLS) or 465 (SSL)
• Security: SSL/TLS
• Authentication: Normal password

Troubleshooting

Check Service Status

systemctl status postfix dovecot amavis spamassassin clamav-daemon opendkim apache2

View Logs

# Postfix logs
tail -f /var/log/mail.log

# Dovecot logs
tail -f /var/log/dovecot.log

# Amavis logs
tail -f /var/log/amavis.log

# Apache logs
tail -f /var/log/apache2/error.log

Test Email Sending

echo "Test email" | mail -s "Test Subject" user@yourdomain.com

Test DKIM

opendkim-testkey -d yourdomain.com -s mail -vvv

Test DNS Records

dig MX yourdomain.com
dig TXT yourdomain.com
dig TXT mail._domainkey.yourdomain.com

Maintenance

Update SSL Certificates

Certificates are automatically renewed via cron. To test renewal:

certbot renew --dry-run

Update Spam Rules

sa-update
systemctl restart spamassassin

Update Virus Definitions

freshclam
systemctl restart clamav-daemon

Backup Configuration

tar -czf email-backup-$(date +%Y%m%d).tar.gz \
  /etc/postfix \
  /etc/dovecot \
  /etc/amavis \
  /etc/opendkim \
  /var/www/postfixadmin/config.local.php \
  /etc/letsencrypt

File Locations

• Postfix config: /etc/postfix/
• Dovecot config: /etc/dovecot/
• Amavis config: /etc/amavis/
• OpenDKIM config: /etc/opendkim/
• PostfixAdmin: /var/www/postfixadmin/
• Mail storage: /var/mail/vhosts/
• SSL certificates: /etc/letsencrypt/live/
• Setup log: /var/log/email-server-setup.log

Advanced Configuration

Custom Spam Rules

Edit /etc/spamassassin/local.cf and restart SpamAssassin.

Additional Domains

Add domains through PostfixAdmin web interface.

Quota Management

Quotas are managed through PostfixAdmin and enforced by Dovecot.

Backup Strategy

Implement regular backups of:

• PostgreSQL database
• Configuration files
• SSL certificates
• Mail data

Support

For issues and support:

1. Check the setup log: /var/log/email-server-setup.log
2. Review service logs
3. Verify DNS configuration
4. Test with online email testing tools

License

This script is provided as-is under the MIT License.