Contents

1. Prerequisites
2. Configure AWS CLI
3. Backup Script
4. Schedule with Cron

Automate daily Mailcow backups to Amazon S3 for off-site protection.

Prerequisites

• AWS account with an S3 bucket created
• IAM user with s3:PutObject and s3:GetObject permissions
• awscli installed on your server

Configure AWS CLI

sudo apt install -y awscli
aws configure
# Enter: Access Key, Secret Key, region (e.g. us-east-1), output format: json

Backup Script

#!/bin/bash
# /opt/mailcow-backup.sh
set -e
DATE=$(date +%Y-%m-%d)
BACKUP_DIR="/tmp/mailcow-${DATE}"
S3_BUCKET="s3://your-backup-bucket/mailcow"

mkdir -p "$BACKUP_DIR"
cd /opt/mailcow-dockerized
docker compose stop

tar -czf "${BACKUP_DIR}/mailcow-${DATE}.tar.gz"   mailcow.conf docker-compose.yml   data/conf data/assets/ssl

docker compose start
aws s3 cp "${BACKUP_DIR}/mailcow-${DATE}.tar.gz" "${S3_BUCKET}/"
rm -rf "$BACKUP_DIR"
echo "Backup complete: mailcow-${DATE}.tar.gz"

chmod +x /opt/mailcow-backup.sh

Schedule with Cron

sudo crontab -e
# Add:
0 2 * * * /opt/mailcow-backup.sh >> /var/log/mailcow-backup.log 2>&1