Univik Mimecast Archive Converter

Mimecast limits each export to ~500MB ZIP batches (delivered as 2GB batches made up of multiple 500MB parts). To export a large mailbox you must generate and download many separate ZIP files. Univik Mimecast Archive Converter solves this automatically — add all your ZIP batches in one session and the converter merges them into a single unified MBOX, PST or PDF output file, treating the entire mailbox as one continuous archive.

Yes, completely offline. Univik Mimecast Archive Converter is a desktop application that processes your archive locally on your Windows PC. No internet connection is required and your email data is never uploaded to any server. Suitable for confidential business correspondence, legal evidence and healthcare data under privacy regulations.

Yes — this is the most common use case. Mimecast EML ZIP exports cannot be opened directly in Outlook. Univik Mimecast Archive Converter converts the EML ZIP batches to a fully importable PST file with all emails, attachments, headers and folder structure preserved. No Outlook installation is required on the conversion machine.

Yes — the full Mimecast header chain is preserved. All headers carry through: standard headers (From, To, CC, Subject, Date, Message-ID), routing headers (Received, Return-Path), Mimecast-specific headers (X-Mimecast-Spam-Score, X-Mimecast-Originator), SPF/DKIM/DMARC results and all X-headers written by Mimecast’s filtering engine. Essential for maintaining legal admissibility of email evidence in eDiscovery proceedings.

Follow these steps: (1) Log into the Mimecast Administration Console, (2) Navigate to Governance & Compliance → Saved Searches, (3) Create and run your search, (4) Right-click the saved search and select Export Search, (5) Choose EML or PST as export format, (6) Monitor progress under Governance & Compliance → Exports & Updates, (7) Download all ZIP batches or PST files when ready, (8) Open Univik Mimecast Archive Converter, load all batches and convert. Note: You cannot export from Archive Search directly — you must use Saved Searches.

Yes, 100% attachment preservation. Every attachment in Mimecast archived emails is preserved: documents (Word, Excel, PDF), images (JPEG, PNG, GIF), archives (ZIP, RAR) and inline embedded content. Attachments that were stubbed in Mimecast are resolved automatically and included in the converted output.

Free trial converts the first 25 emails per archive. All features are fully functional — all 10+ export formats, ZIP batch merging, preview, date filtering and Mimecast-specific header handling. No time limit. Verify that Mimecast header fields and attachment handling meet your requirements before purchasing ($29 personal, $99 business/MSP).

Minimal requirements:

• OS: Windows 11, 10, 8.1, 8 or 7 (32-bit and 64-bit)
• RAM: 2 GB minimum (4 GB recommended for large archives)
• Disk Space: 50 MB for installation
• Framework: .NET Framework 4.8 or higher

No Outlook, SQL Server or any other software dependency required.

If you only need to browse and read your Mimecast archived emails without converting, use the free Univik Mimecast Viewer to open ZIP exports and preview emails at no cost. Use it first if you are still assessing your archive before committing to a migration format.