In Office web add-ins you can make Fetch API requests. The Fetch API
provides an interface for fetching resources (including across the network). It will seem familiar to anyone who has used XMLHttpRequest
, but the new API provides a more powerful and flexible feature set.
The On-send feature for Outlook add-ins provides a way to handle a message or meeting item, or block users from certain actions, and allows an add-in to set certain properties on send, where you could also make a web call.
A lightweight launch events also can be considered, see Use Smart Alerts and the OnMessageSend and OnAppointmentSend events in your Outlook add-in for more information. The OnMessageSend
and OnAppointmentSend
events take advantage of Smart Alerts
, which allows you to run logic after a user selects Send
in their Outlook message or appointment. Your event handler allows you to give your users the opportunity to improve their emails and meeting invites before they're sent. Be aware, the OnMessageSend
and OnAppointmentSend
events were introduced in requirement set 1.12.
See Differences between Smart Alerts and the on-send feature for more information.