The classic VSTO add-in is for users on classic Outlook (desktop, Windows) and requires administrator rights to install. The new web-based add-in supports new Outlook, Outlook on the web, Outlook for Mac, and classic Outlook 2016 or later, and is normally deployed centrally by an IT administrator, though individual users can install it themselves where their organisation's policy permits.

Classic Outlook (desktop)

Classic Add-In (VSTO)

For users on classic Outlook for Windows

The classic Outlook Add-In lets you upload and attach emails to records in WebTMS, and compose new emails by merging WebTMS records with template emails from the WebTMS Document Library. Installed per machine by an administrator. Compatible with Outlook 2010 and later on Microsoft Windows.

Only use this for classic Outlook (desktop, Windows). For new Outlook, Outlook on the web, or Outlook for Mac, use the new web-based add-in instead.
  • Classic Outlook 2010 or later (Windows only)
  • Administrator rights required to install
  • Installed per machine, not centrally deployed
Current version v3.2f (07/01/2026)
Download VSTO Add-In Download user manual (PDF)
New Outlook, web & Mac

New Outlook Add-In

Deployed centrally via Microsoft 365

The new web-based add-in supports new Outlook, Outlook on the web, Outlook for Mac, and classic Outlook 2016 or later. It is normally deployed centrally by an IT administrator via the Microsoft 365 Admin Centre. Where an organisation's policy permits, individual users can also install it themselves.

  • New Outlook, Outlook on the web, Outlook for Mac
  • Classic Outlook 2016 or later (Windows or Mac)
  • Microsoft 365 required
  • Central deployment requires Global Admin or Exchange Admin role
Go to deployment guide Download user manual (PDF)