Mario B.-Senior IT Consultant | Exchange & Messaging | Vulnerability Management
Check rate
Experience
Project Lead & Consultant DMARC/Email Authentication, Exchange
Comedia. IT GmbH
Goal:
Protect customer domains from spoofing by establishing and securing DMARC compliance, and ensure secure and stable operation of the Exchange and Microsoft 365 environment while keeping legitimate mail flows running smoothly.
Responsibilities:
- Project management, including reporting, customer coordination and budget responsibility
- Set up and secure DMARC, including DKIM and SPF
- Ongoing analysis of DMARC reports to detect and resolve issues early
- Replace EWS connections before Microsoft's shutdown on 01.10.2026 by switching to Microsoft Graph
- Introduce sensitivity labels in Microsoft Purview to protect sensitive information
- Automate recurring administrative tasks with PowerShell
- 3rd Level Support and ongoing administration of Exchange Online and Exchange on-premises
Technologies: Exchange Online, Exchange Server (on-premises), Microsoft 365, Microsoft Graph API, EWS, Microsoft Purview / Sensitivity Labels, DMARC, DKIM, SPF, RUA-Reporting, PowerShell, HCL Notes
Microsoft Exchange Consultant
DVAG (über compeople AG)
Goal:
Operate, improve and secure the Exchange hybrid infrastructure, including full email authentication.
Responsibilities:
- Administration and engineering of the Exchange hybrid infrastructure (2019/SE/Online), including SMTP mail flow design and connector configuration
- Mailbox migrations as part of the ongoing expansion of the hybrid infrastructure
- Set up and maintain email authentication with SPF, DKIM and DMARC
- Troubleshoot complex mail flow issues, including analysis of message tracking logs and certificate-based authentication
- Set up and administer OnTime (Intravision) and the GBS iQ.Suite and Exclaimer signature/disclaimer solutions
- Configure anti-spoofing policies in the Microsoft 365 Defender portal and compliance settings (eDiscovery) in Microsoft Purview
- Run vulnerability scans on Exchange servers with Rapid7 InsightVM and remediate findings
- Prepare technical documentation and hand over to the operations team
Result:
- 700 mailboxes migrated while keeping the hybrid infrastructure running; a noticeable reduction in delivery failures through the gradual tightening of the DMARC policy.
Technologies: Exchange 2019/SE, Exchange Online, Azure, Entra ID, Microsoft 365 Defender, Microsoft Purview, GBS iQ.Suite, Exclaimer, OnTime, Microsoft Graph API, Rapid7 InsightVM
Vulnerability Manager
KfW Bankengruppe
Goal:
Operate and improve the vulnerability management service in a complex, regulated banking environment.
Responsibilities:
- Plan, conduct and manage vulnerability and compliance scans with Rapid7 Nexpose/InsightVM based on CIS Benchmarks
- Review compliance gaps on Windows and Linux servers, assess risks and prioritize them in coordination with business units
- Manage remediation through ServiceNow tickets with deadlines based on severity
- Improve vulnerability management processes and policies in line with BAIT/MaRisk
- Report on the vulnerability landscape to ISB/Information Security
- Prepare the technical documentation for an EU-wide tender for a new vulnerability management solution: market research, specification (requirements document) with mandatory and optional criteria, evaluation matrix and award memo
Result:
Improved vulnerability management process with more precise prioritization and fewer false positives in reporting; a fully prepared EU tender as the basis for the replacement solution.
Technologies: Rapid7 Nexpose/InsightVM, CIS Benchmarks, Windows Server, Red Hat Enterprise Linux, ServiceNow, HP Service Manager
IT Engineer
Goal:
Build basic IT infrastructure for a small company in the construction industry.
Responsibilities:
- Plan and build the network infrastructure (LAN, WAN, DMZ, Management LAN), including a Sophos firewall
- Build the Active Directory infrastructure with domain controller, DNS and DHCP
- Set up a two-tier AD PKI (Standalone Offline Root CA, Enterprise Subordinate CA)
- Install and configure Microsoft Exchange 2019 (On-Premises)
- Hand over the system and train employees
Result:
Completed the full IT infrastructure build and successfully handed it over to the customer's operations team.
Technologies: Windows Server 2019, Active Directory, PKI/Certificate Services, Sophos XG/SFOS, Microsoft Exchange 2019, DNS, DHCP
Vulnerability Manager
ITERGO/ERGO Versicherungsgruppe
Goal:
Build a vulnerability management service from tool selection through ongoing operations, including handover to a nearshore service provider.
Responsibilities:
- Prepare a technical concept and comparative proof of concept for Tenable (Nessus), Rapid7 and Qualys to select a new vulnerability management solution; selected Tenable
- Set up and administer the vulnerability management service (Plan/Build/Run) using Tenable.sc and Nessus
- Conduct and review vulnerability and compliance scans on Windows and Linux servers
- Manage and escalate security incidents
- Develop processes, policies and documentation (installation and operations manual, vulnerability reports for management)
- Transition the service to the nearshore provider
Result:
Successfully launched the vulnerability management service and handed it over to the nearshore provider.
Technologies: Tenable.sc (SecurityCenter), Nessus Scanner/Manager/Agents, Rapid7 and Qualys (PoC), PowerShell, Windows Server, Red Hat Enterprise Linux
Unified Messaging Engineer
ITERGO Informationstechnologie
Goal:
Operate and further develop the Unified Communication infrastructure for the ITERGO/ERGO Group, supporting more than 30,000 mailboxes.
Responsibilities:
- Administer and maintain Exchange servers and DAGs (Exchange 2007/2013)
- Provide 2nd- and 3rd-level support for BlackBerry Enterprise Service (BES10/12), including user migration and transition to Citrix XenMobile 10
- Introduce and maintain Skype for Business
- Migrate the mail security solution from Microsoft Forefront to Trend Micro ScanMail for Exchange
- Transition to the new service provider CSC/DXC
Result:
Successfully migrated BlackBerry users from BES10 to BES12 and smoothly handed over the infrastructure to the new service provider.
Technologies: Exchange 2007/2013, BlackBerry Enterprise Server 10/12, Citrix XenMobile 10, Skype for Business 2015, TrendMicro ScanMail for Exchange, PowerShell
MDM & BlackBerry
Alstom Deutschland AG
Many years of experience in Mobile Device Management, Unified Communication and traditional system administration in large corporations, the telecommunications sector and the public sector.
BlackBerry Enterprise Server, AirWatch, Citrix XenMobile, Good for Enterprise
MDM & BlackBerry
BWI Informationstechnik (Bundeswehr)
Many years of experience in Mobile Device Management, Unified Communication and traditional system administration in large corporations, the telecommunications sector and the public sector.
BlackBerry Enterprise Server, AirWatch, Citrix XenMobile, Good for Enterprise
MDM & BlackBerry
Daimler AG
Many years of experience in Mobile Device Management, Unified Communication and traditional system administration in large corporations, the telecommunications sector and the public sector.
BlackBerry Enterprise Server, AirWatch, Citrix XenMobile, Good for Enterprise
MDM & BlackBerry
Hessische Zentrale für Datenverarbeitung (HZD)
Many years of experience in Mobile Device Management, Unified Communication and traditional system administration in large corporations, the telecommunications sector and the public sector.
BlackBerry Enterprise Server, AirWatch, Citrix XenMobile, Good for Enterprise
MDM & BlackBerry
Norddeutsche Landesbank (Nord/LB)
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
BlackBerry-Enterprise-Server, AirWatch, Citrix XenMobile, Good for Enterprise
MDM & BlackBerry
Wincor Nixdorf
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
BlackBerry-Enterprise-Server, AirWatch, Citrix XenMobile, Good for Enterprise
Groupware, Server Operations, Rollout, Provider Management
Bayer AG
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
Deutsche Post
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
HSH Nordbank
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
Hewlett Packard
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
Lufthansa Systems
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
Telekom
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
Vodafone
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Groupware, Server Operations, Rollout, Provider Management
dwpbank
Many years of experience in Mobile Device Management, Unified Communication, and traditional system administration at large corporations, in the telecommunications sector, and in public service.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Banking and Finance, Information Technology, Government and Administration, Telecommunication, Manufacturing, and Aerospace and Defense.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Procurement, Customer Service, and Project Management.
Summary
As a Senior IT Consultant, I bring more than 25 years of IT experience, most of it in building, operating and securing messaging infrastructures. My focus is Exchange – on-premises, hybrid or Exchange Online, depending on the customer's cloud strategy. This includes administration, engineering and migration, as well as connecting third-party systems (e.g. mail security gateways and signature solutions), full email authentication (SPF, DKIM, DMARC) and hardening mail transport security. I also have many years of experience in IT and cloud security, with a focus on vulnerability management, including Microsoft 365 Defender, Tenable and Rapid7. Azure/Entra ID, Mobile Device Management and IT Service Management round out my profile. My project experience includes banks and insurance companies, public administration, and the telecommunications and automotive industries. I work independently, document my work thoroughly and ensure structured handovers.
Skills
Exchange & Messaging
- Exchange On-Premises, Hybrid And Exchange Online, Including High Availability And Certificate Management (Dags, Load Balancing) And Microsoft Graph Api
- Email Authentication (Spf, Dkim, Dmarc), Smtp Mail Routing And Integration Of Mail Security Gateways
- Compliance & Retention (Ediscovery, Litigation Hold, Transport Rules, Dlp)
- Powershell-Based Automation Of Recurring Administrative Tasks
- Microsoft Exchange (On-Prem, Hybrid, Online) – > 10 Years
- Exchange Online Protection (Eop) – 5 Years
- Microsoft Graph Api – 1 Year
- Hcl Notes/Domino – 9 Years
Vulnerability Management & It Security
- Building, Operating And Improving Vulnerability Management Services (E.G. Microsoft 365 Defender, Tenable, Rapid7), As Well As Compliance Scans (E.G. Based On Cis Benchmarks) And Defining Hardening Measures
- Security Incident Management And Escalation Processes
- Firewall And Network Security (E.G. Sophos Xg, Fortinet)
- Risk Assessment, Prioritization Of Findings And Reporting
- Spf, Dkim, Dmarc (Including Rua Reporting) – 3 Years
- Microsoft 365 – 5 Years
- Azure, Entra Id – 5 Years
- Microsoft 365 Defender – 5 Years
- Microsoft Purview (Ediscovery) – 3 Years
- Rapid7 Nexpose/Insightvm – 2 Years
- Tenable.Sc, Nessus – 3 Years
- Qualys – < 1 Year
- Cis Benchmarks – 3 Years
Firewall & Network Security
- Sophos Xg/Sfos – 3 Years
- Fortinet, Fortios – 2 Years
- Lancom – 2 Years
Mobile Device Management
- Microsoft Intune – 3 Years
- As Well As Several Years Of Experience With Other Mdm Platforms
Automation & Infrastructure
- Powershell – 7 Years
- Active Directory – > 10 Years
- Windows Server – > 10 Years
- Linux (Red Hat, Centos) – 5 Years
Third-Party Systems
- Gbs Iq.Suite – 5 Years
- Exclaimer – 5 Years
- Ontime (Intravision) – 5 Years
Languages
Education
FH Trier
International Business · Trier, Germany
Vocational School
Apprenticeship as a Retail Salesperson · Germany
Certifications & licenses
Sophos Certified Engineer (XG Firewall)
LANCOM Certified Specialist (LCS)
CLP Domino Application Developer
Principal CLP Domino System Administrator
Statistics
Experience
Global experience
Expertise
Qualifications
Frequently asked questions
Have questions? Find more information here.
Mario is based in Türkheim, Germany.
Mario speaks the following languages: German (Native), English (Advanced), Russian (Intermediate), Spanish (Elementary).
Mario has at least 28 years of experience. During this time, Mario has worked in at least 7 different roles and for 19 different companies. The average length of individual experience is 1 year and 5 months. Note that Mario may not have shared all experience and actually has more experience.
Based on recent experience, Mario would be well-suited for roles such as: Project Lead & Consultant DMARC/Email Authentication, Exchange, Microsoft Exchange Consultant, Vulnerability Manager.
Mario's most recent position is Project Lead & Consultant DMARC/Email Authentication, Exchange at Comedia. IT GmbH.
In recent years, Mario has worked for Comedia. IT GmbH and DVAG (über compeople AG).
Mario is most experienced in industries like Banking and Finance, Information Technology, and Government and Administration. Mario also has some experience in Telecommunication, Manufacturing, and Aerospace and Defense.
Mario is most experienced in business areas like Information Technology, Procurement, and Customer Service. Mario also has some experience in Project Management.
Mario has recently worked in industries like Banking and Finance and Information Technology.
Mario has recently worked in business areas like Information Technology, Customer Service, and Project Management.
Mario attended FH Trier for International Business.
Mario has 6 certificates. Among them, these include: Sophos Certified Engineer (XG Firewall), LANCOM Certified Specialist (LCS), and Microsoft Certified Technology Specialist (MCTS).
Mario will be available full-time from November 2026.
Daily rate distribution
The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.
Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 29 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Similar freelancers
Discover other experts with similar qualifications and experience
Miguel S.
Markus H.
Vicenco K.
Andreas E.
Christian F.
Jin-Ho Y.
Frank J.
Daniel J.
Alagi M.
Andreas F.
Experts recently working on similar projects
Freelancers with hands-on experience in comparable project as a Project Lead & Consultant DMARC/Email Authentication, Exchange
Mohammed N.
Thomas R.
Christian E.
Wilhelm H.
Ornel Franck W.
Christian D.
Mark O.
Peter F.
Sascha P.
Marco Z.
Nearby freelancers
Professionals working in or nearby Türkheim, Germany
Jan B.
Jürgen K.
Denis D.
Dieter S.
Rainer V.
Anton P.
Enver B.
Detlef H.
Carl-Friedrich L.
Andreas T.
