Office.context.mailbox.item.inReplyTo is not available on item being composed in Outlook

[cody-lettau]

Provide required information needed to triage your issue

The new Office.context.mailbox.item.inReplyTo property is not available on an item being composed in reply to an item or when forwarding an item.

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: OWA
• Host [Excel, Word, PowerPoint, etc.]: Outlook
• Browser (if using Office on the web): Chrome

Expected behavior

I would expect that the parent message id value is available on this property (Office.context.mailbox.item.inReplyTo).

Current behavior

The property does not exist on the item, resulting in undefined if used. This was seen in OWA (did not test on Windows or Mac).

Steps to reproduce

1. Click to reply to an existing message.
2. In an on-send or compose add-in, check Office.context.mailbox.item.inReplyTo for the parent id.

Provide additional details

1. I would like to know if this should be expected to work in an on-premise Exchange environment if the user is using a Windows Desktop client (as long as the client platform/version says it supports Mailbox 1.14 req set, even if Exchange On-prem says up to 1.5 req set only)?

Context

Add-ins need the ability to easily get the message id of the item being replied to or forwarded. Relying on Rest/Graph/EWS is not sufficient as it takes time for the item to be synced to Exchange and then it takes multiple calls to actually get the correct/usable ID (I have tried this using EWS as I have an on-prem requirement).

[github-actions]

Here are some similar issues that might help you. Please check if they can solve your problem.

• ConversationId is 'null' in new OWA even on reply #636
• inReplyTo property of the compose message is empty on Outlook for Mac #4786
• Mailbox item is undefined in compose mode (macOS Client 16.85) #4538
• Office.context.mailbox.item undefined when switching between inline replies with pinned task pane #2295
• Item doesn't contain item id in On send event for Office JS Outlook #624

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Possible solution (Extracted from existing issue, might be incorrect; please verify carefully)

Solution 1:

Thanks for linking the docs, as suggested, we now check for the presence of Item in the change handler.

Reference:

• Office.context.mailbox.item undefined when switching between inline replies with pinned task pane #2295 (comment)

Solution 2:

I believe this is the default behavior in Desktop Outlook, for which we have documented a guideline to always check for null before doing any work in the ItemChanged event handler, on this page.

Reference:

• Office.context.mailbox.item undefined when switching between inline replies with pinned task pane #2295 (comment)