GainTools Merge PST vs TrustVare OLM to Office 365 Converter

Converts OLM to Office 365 format, not PST merging.

Side by side

What it is: GainTools Merge PST:GainTools Merge PST merges multiple Outlook PST files into one without data loss.; TrustVare OLM to Office 365 Converter:Converts Mac Outlook OLM files to Office 365 accounts while preserving structure and attachments.
Best for: GainTools Merge PST:Merging Outlook PST files on Windows; TrustVare OLM to Office 365 Converter:Bulk OLM-to-Office365 migration
Who it’s for: GainTools Merge PST:IT admins, support staff, and users who need to combine Outlook PST archives.; TrustVare OLM to Office 365 Converter:IT teams, businesses and individuals migrating from Mac Outlook to Office 365.
Pricing: GainTools Merge PST:Freemium; TrustVare OLM to Office 365 Converter:Freemium
Works with: GainTools Merge PST:—; TrustVare OLM to Office 365 Converter:Office 365
DevHunt upvotes: GainTools Merge PST:0; TrustVare OLM to Office 365 Converter:1
Launched on DevHunt: GainTools Merge PST:Jan 2026; TrustVare OLM to Office 365 Converter:Jun 2025

Combine multiple PSTs. Merge any number of ANSI or Unicode PST files into a single PST.
Preserve folder structure. Keeps original email layout, folders, contacts, calendar and attachments intact.
Password-protected PST support. Can merge PST files that are secured with a password.
Selective folder merge. Choose to merge entire PSTs or only specific folders such as Inbox or Contacts.
Custom output folders. Save the merged PST in a new folder or create separate folders per source PST.
No file-size limit. Handles PST files of any size on supported Windows versions.
Fast, accurate merging. Processes merges quickly while retaining all mail properties without corruption.
Simple wizard UI. Step-by-step interface guides users through loading, selecting, and merging PSTs.

Full mailbox export. Transfers emails, contacts, calendars and attachments from OLM to Office 365.
Preserves formatting. Keeps original folder structure, metadata and formatting intact.
Bulk conversion. Exports unlimited OLM files in one operation.
Automatic Office 365 login. Connects to the target account after entering credentials.
Preview pane & log report. Shows data preview and generates a log of the exported items.
No Outlook required. Runs as a standalone Windows app without installing Outlook.

Based on each tool's website and DevHunt data. Details may change; check the official sites.