Smart Alerts block addin from sending

[mikey8808]

Provide required information needed to triage your issue

When sending an email smart alerts blocks our addin from sending. Visible is Smart Alerts soft block dialog and the only option is to "don't send".
We can see that our addin stops processing once the the below is shown in console in devtools.

We have not made any changes in our addin and this had starting to happen 1.12.2025.

Your Environment

• Platform [Mac, NewOutlook, Office on the web]

Expected behavior

Addin finishes processing, softblock dialog closes and email sends. No console errors.

Current behavior

Addin stops processing, softblock dialog remains open and email can't be sent. Console errors are shown; ('l_AttachmentExceededSize_Text').

Steps to reproduce

1. Send an email that has onSend functionality.

[TeeJayKB4]

Hi @exextoc, please could we get any update on the issue raised. it's a blocker for our process. Thanks.

[jsunkara-msft]

Hi @mikey8808 can you please provide details from your manifest?

[TeeJayKB4]

Hi @jsunkara-msft, please could you provide a secure way to share the manifest with you? Or what details of the manifest are you inetrested in? .. Oh, I am a colleague of @mikey8808

[TeeJayKB4]

Hi @jsunkara-msft,

Please find the requested document in the repo and a readme guide to replicating the issue. https://github.com/TeeJayKB4/EPS-1517

Thanks

[jsunkara-msft]

Thank you @TeeJayKB4 taking a look now, will provide you with an update.

[TeeJayKB4]

Hi @jsunkara-msft

Any update on this please?

[jsunkara-msft]

Hi @TeeJayKB4, sorry for the late reply may I know which API you are using for attaching the files? Incase you are using the addFileAttachmentFromBase64Async there is a character limitation which may cause this message to appear. Can you please confirm which API is being used?
Documentation: https://learn.microsoft.com/en-us/javascript/api/outlook/office.messagecompose?view=outlook-js-preview

[TeeJayKB4]

Hi @jsunkara-msft,

thanks for getting back. we are not using that API, we use the "Office.context.mailbox.item.getAttachmentContentAsync()" to get the content. we don't make use of the mentioned API in our codebase.

Mor importantly, we get the issue reported here even when we don't have any attachment on the email. A simple email does that too.

Please, reach out if more info is needed, really happy to help get this resolved because it's holding us too.