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Corporate VoIP & Mail Systems

Architecture, integration, and round-the-clock maintenance of mission-critical corporate communications: high-availability IP telephony and hardened enterprise mail servers. Noxet engineers design sovereign on-premise and hybrid communication backbones that eliminate expensive per-user SaaS license fees and safeguard corporate communication privacy.

We ensure crystal-clear voice transmission without packet jitter or echo, 99.9% uptime, and flawless email deliverability to your business partners and customers worldwide.

Capabilities & Solutions

  • Corporate IP Telephony (Asterisk, FreePBX, Cisco CUCM):

    • Deployment and management of IP PBX platforms on Asterisk, FreePBX, and Issabel, alongside enterprise Cisco Unified Communications Manager (CUCM) clusters.
    • SIP trunk peering with telecom carriers, multi-line DID routing, outbound least-cost routing, and failover channels.
    • Interactive Voice Response (IVR) menus, automated call distribution queues, time-based routing schedules, and mobile twinning.
    • Encrypted call recording with granular role-based search and playback web consoles, accompanied by comprehensive Call Detail Record (CDR) analytics.
    • Deep CRM integration (1C:Enterprise, Bitrix24, amoCRM, custom CRM platforms) enabling click-to-dial and automatic customer card popups.
    • Remote workforce mobility: WebRTC gateways and secure softphones connecting via TLS/SRTP from mobile devices and laptops without dedicated hardware deskphones.

  • VoIP Security & Anti-Fraud Protection:

    • Active defense against SIP brute-force attempts and automated scanning (Fail2ban, VoIP firewalls, nftables rate limiting).
    • Comprehensive toll-fraud prevention: automated detection of suspicious calling patterns and hard limits on high-cost international destinations.
    • Voice payload and signaling encryption (SRTP / SIP over TLS) protecting corporate conversations against network eavesdropping.

  • Enterprise Mail Infrastructure (Exchange, CommuniGate Pro, Linux):

    • High-availability Microsoft Exchange Server clusters utilizing Database Availability Groups (DAG), load-balanced Client Access Services, and hybrid Office 365 setups.
    • On-premise deployment of CommuniGate Pro: enterprise-grade unified communications providing email, calendars, contacts, and instant messaging.
    • Resilient open-source Linux mail platforms: Postfix + Dovecot + Rspamd stack paired with modern webmail (Roundcube / SOGo) and centralized Active Directory / FreeIPA authentication.

  • Email Deliverability & Spam Defense:

    • End-to-end cryptographic domain identity setup: strict SPF, high-bit DKIM signing, enforced DMARC policies (p=quarantine / p=reject), and proper reverse DNS (PTR) mapping.
    • Advanced spam, phishing, and malware filtering powered by Rspamd neural network scoring, dynamic DNSBL reputation lists, and greylisting.
    • Real-time attachment sandboxing and scanning with ClamAV to neutralize malicious payloads before reaching inboxes.
    • Mandatory STARTTLS / TLS encryption for all inter-server mail relays.

  • Zero-Downtime Migration & Data Protection:

    • Seamless mailbox migrations from cloud providers (Google Workspace, Microsoft 365, local hosting) to internal infrastructure without operational disruptions.
    • Automated point-in-time backups of mailbox databases and PBX configurations with regular test restores.

Technology Stack

  • Telephony Platforms: Asterisk, FreePBX, Issabel, Cisco CUCM, Kamailio, SIP/RTP, TLS/SRTP, WebRTC.
  • Mail Platforms: Microsoft Exchange Server (DAG), CommuniGate Pro, Postfix, Dovecot, Exim.
  • Security & Filtering: Rspamd, SpamAssassin, ClamAV, Fail2ban, DMARC, DKIM, SPF, TLS.
  • Clients & Webmail: Roundcube, SOGo, Nextcloud Mail, Microsoft Outlook, Thunderbird.
  • Hardware & Softphones: Cisco, Yealink, Grandstream, MicroSIP, Linphone, Telephone.

Deliverables Provided to Clients

  1. Total Sovereignty & Zero Per-Seat Licensing: Full ownership of your voice and email infrastructure with predictable running costs.
  2. High-Availability Architecture: Resilient telephony and mail systems engineered without single points of failure.
  3. Flawless Domain Reputation: Guaranteed inbox delivery without false positive spam flags or blacklisting.
  4. Hardened Perimeter: Elimination of toll fraud risks and end-to-end protection of confidential correspondence.
  5. 24/7 SLA Support: Proactive monitoring of SIP trunk and mail queue health with rapid engineer response.
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