Issue with CID Image in Outlook when Migrating from Windows-Legacy to Windows (.NET 5+) – No COM Interop / No SMTP

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Hi ,

We are currently migrating our processes from Windows-Legacy to Windows (.NET 5+), as UiPath has announced the deprecation of the legacy framework.

One of our workflows involves sending emails with CID embedded images, which was implemented using Invoke Code and the Microsoft.Office.Interop.Outlook COM library.
We chose this method because the standard “Send Outlook Mail Message” activity sometimes fails to render CID images properly in certain Outlook Online mailboxes.
To ensure reliability, we used the official Outlook COM API to create attachments with specific CIDs.

However, after migrating to the Windows (.NET 5+) compatibility, we encountered an issue:

:red_exclamation_mark: “COM reference to Microsoft.Office.Interop.Outlook is not supported in .NET 5+”

Unfortunately, SMTP cannot be used in our organization due to security policies, so that option is not available either.

:magnifying_glass_tilted_left: My Questions:

  1. Is there any workaround to send CID embedded images in Windows (.NET 5+) projects?
  2. Will the Send Outlook Mail Message activity support CID-based image embedding in the future (e.g., allowing us to set cid:image1 and bind an attachment ID directly)?

This issue is critical to our business process, so any advice or roadmap information would be greatly appreciated.

Thank you!

2

@heyjinp

I believe mailkit does support cid

cheers

3

@Anil_G
Thank you for your reply! I understand that MailKit supports CID. However, since MailKit is provided as a DLL, is it actually possible to call it directly from UiPath? Also, due to company security policies, we cannot use an SMTP server. Thanks again for your help!

4

@heyjinp

In manage packages you can find mailkit already

If smtp is an issue then you need to try your luck with latest outlook

Cheers

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