CLOUD SERVER FOR EMAIL
Infrastructure Specifications
Technical Specifications for Managed Email Infrastructure
Technical senders evaluating email infrastructure need specific, verifiable specifications — not marketing language. This page documents the exact software versions, hardware configurations, datacenter specifications, and configuration parameters available in Cloud Server for Email's managed infrastructure environments.
Specifications are current as of April 2026. Software versions are updated regularly; contact infrastructure@cloudserverforemail.com to confirm current versions for a specific engagement.
Software Stack
| Component | Software | Current Version | Update Policy |
|---|
| Mail Transfer Agent | PowerMTA (Port25/Zeta) | 5.5.x (current release) | Minor updates within 30 days of release; major versions tested before deployment |
| Campaign Platform | MailWizz EMS | 2.x (current stable) | Quarterly major updates; security patches within 7 days |
| Operating System | AlmaLinux 9 / Ubuntu 24.04 LTS | Current LTS | Security patches automated (kernel monthly) |
| Web Server (MailWizz) | Nginx + PHP-FPM | Nginx 1.24+, PHP 8.2+ | Security patches within 7 days |
| Database | MySQL 8.0 / MariaDB 10.11 | Current stable | Minor: automated; major: tested 30 days |
| DNS/PTR Management | RIPE NCC allocation | N/A | PTR records updated same-day upon request |
| SSL/TLS (tracking domains) | Let's Encrypt / custom cert | TLS 1.2 minimum, TLS 1.3 preferred | Auto-renewal 30 days before expiry |
| Firewall | nftables / UFW | Current OS release | Rules updated as required for security |
Hardware Specifications by Plan
| Specification | Foundation | Production | Enterprise |
|---|
| CPU | 4 cores / 2.8 GHz+ | 8 cores / 3.0 GHz+ | 16+ cores / 3.2 GHz+ |
| RAM | 16 GB ECC | 32 GB ECC | 64 GB ECC |
| Storage (OS + App) | 240 GB NVMe SSD | 480 GB NVMe SSD | 960 GB NVMe SSD RAID-1 |
| Storage (PowerMTA Spool) | 240 GB NVMe (dedicated partition) | 480 GB NVMe (dedicated) | 960 GB NVMe RAID-1 (dedicated) |
| Network uplink | 1 Gbps dedicated | 1 Gbps dedicated | 10 Gbps dedicated |
| Network redundancy | Single uplink | Single uplink | Dual uplink (BGP failover) |
| Power redundancy | N+1 datacenter UPS | N+1 datacenter UPS | 2N datacenter UPS |
| Hardware generation | Current gen (< 2 years) | Current gen (< 2 years) | Current gen (< 1 year) |
Datacenter Specifications
| Specification | Details |
|---|
| Location | with EU and global infrastructure, European Union |
| Tier classification | Tier III (concurrent maintainability) |
| Power availability | 99.982% per datacenter SLA |
| Cooling | N+1 precision cooling |
| Physical security | 24/7 on-site security, biometric access, CCTV, mantrap entry |
| Fire suppression | Gaseous suppression (FM-200 / Novec 1230) |
| Network carriers | Telia, Elisa, local IXP (TLL-IX) with DE-CIX Frankfurt peering |
| IP jurisdiction | RIPE NCC (European Internet Registry) — the EUn allocation |
| Legal jurisdiction | Republic of the EU (EU member state) |
| Data protection law | GDPR (EU Regulation 2016/679) — applies directly |
Network and IP Infrastructure
IP Address Allocation
| Parameter | Standard | Notes |
|---|
| IP registry | RIPE NCC | European allocation — verifiable via whois |
| IP assignment type | Static dedicated | IPs assigned exclusively to client for contract duration |
| Minimum IP allocation | 1 IP | Foundation plan includes 2 IPs |
| Maximum IPs per server | Unlimited (practical limit: 16–20) | Subject to routing table size |
| IPv4 availability | Yes | All sending IPs are IPv4 |
| IPv6 availability | Yes (optional) | Available for sending but not required |
| rDNS (PTR record) | Configured for all IPs | Matches PowerMTA EHLO hostname; same-day update capability |
| FBL enrollment | Yahoo, Comcast | Registered per client domain/IP combination |
Connectivity
- Direct peering at TLL-IX (Tallinn Internet Exchange) — low-latency access to Baltic and Nordic ISPs
- DE-CIX Frankfurt peering via carrier — low-latency access to German ISPs (GMX, T-Online, Web.de)
- AMS-IX Amsterdam peering via carrier — access to Dutch and Western European ISPs
- Transit connections: Telia Carrier (AS1299), providing global IPv4 and IPv6 reach
- Average latency to Gmail (Google): 18–22ms; Outlook (Microsoft): 20–25ms; Yahoo: 95–110ms (US-hosted)
- Average latency to European ISPs: GMX/Web.de: 12–18ms; Orange.fr: 22–28ms; T-Online: 18–24ms
PowerMTA Configuration Parameters
Default Per-ISP Domain Block Configuration (Production)
The following parameters represent the default starting configuration for new infrastructure deployments. These are adjusted based on IP reputation data within the first 30 days of operation:
| ISP | max-smtp-out | max-msg-rate | retry-after | max-msg-per-conn |
|---|
| Gmail (gmail.com) | 8 (HIGH rep) | 3,500/h | 15m | 100 |
| Microsoft (outlook.com) | 5 | 2,000/h | 25m | 50 |
| Yahoo (yahoo.com) | 6 | 2,500/h | 20m | 100 |
| GMX / Web.de | 4 | 1,500/h | 30m | 50 |
| T-Online (telekom.de) | 3 | 1,200/h | 30m | 50 |
| Orange.fr | 3 | 1,000/h | 30m | 30 |
| Default (all others) | 3 | 800/h | 30m | 30 |
These are starting values for HIGH IP reputation. Production values are adjusted based on observed deferral rates and Postmaster Tools/SNDS data. Lower values are used during IP warming and for IPs at MEDIUM or LOW reputation.
Authentication Configuration
| Authentication | Standard | Implementation |
|---|
| SPF | PASS required | SPF record includes all sending IPs; SoftFail (~all) minimum; Fail (-all) where possible |
| DKIM | 2048-bit RSA, per-domain keys | Separate key per sending domain; rotation every 12 months minimum; PowerMTA native signing |
| DMARC | p=reject target (p=none initially) | Start at p=none with rua reporting; advance to p=quarantine within 60 days; p=reject within 90 days |
| BIMI | Optional (VMC required) | Configured upon client request; requires DMARC at enforcement and Verified Mark Certificate |
| PTR/rDNS | Required for all IPs | Forward-confirmed reverse DNS for every sending IP; matches PowerMTA EHLO hostname |
| TLS (outbound) | Opportunistic TLS (STARTTLS) | TLS 1.2 minimum; TLS 1.3 where supported by receiving server |
| TLS (MailWizz tracking) | Required | Let's Encrypt or custom certificate; HTTPS enforced for tracking domains |
Monitoring Infrastructure
Automated Monitoring Systems
- PowerMTA accounting log real-time streaming: each delivery event logged to accounting CSV with 200ms maximum write latency
- Automated deferral rate calculation: hourly per-ISP deferral rate from accounting log; alert triggers at 8% sustained for 2 hours
- Google Postmaster Tools API integration: domain reputation and spam rate checked daily at 08:00 CET
- Microsoft SNDS API: IP status checked daily at 08:30 CET; immediate alert on Red status
- Blacklist monitoring: all sending IPs checked against 50+ lists every 6 hours; immediate alert on new listing
- MailWizz cron job monitoring: execution confirmed every 5 minutes; alert if cron job fails to run within 10 minutes of schedule
- Server health monitoring: CPU, RAM, disk utilization, network throughput checked every 60 seconds
- SSL certificate expiry monitoring: alert at 30 days, 14 days, 7 days before expiry
Backup and Recovery
| What | Frequency | Retention | Recovery Time Target |
|---|
| PowerMTA configuration files | Daily | 30 days | < 1 hour |
| MailWizz application + config | Daily | 30 days | < 2 hours |
| Subscriber database (MySQL) | Daily incremental, weekly full | 90 days | < 4 hours |
| DKIM private keys | Immediately on creation | Indefinite (encrypted) | < 30 minutes |
| PowerMTA accounting logs | Not backed up (ephemeral operational data) | N/A | N/A |
| Server snapshots | Weekly | 4 weeks | < 30 minutes (full server restore) |
Custom Specifications AvailableEnterprise clients with specific requirements — different server locations within the EU, custom hardware configurations, specific software versions, or dedicated network segments — can discuss custom specifications during the technical assessment process. Contact infrastructure@cloudserverforemail.com for custom infrastructure requirements.
Discuss Infrastructure Requirements
Cloud Server for Email operates managed PowerMTA + MailWizz infrastructure from EU servers.
Dedicated IPs, daily monitoring, GDPR compliance by design.
