Power Platform Community Forum Thread Details

Hi everyone,

I’m running into an issue with corrupted email attachments in a Power Automate flow and I can’t figure out where the encoding breaks.

Scenario

I have a cloud flow that:

Triggers when a new email arrives in a shared mailbox
Runs the content through a Copilot/AI agent to classify it
Depending on the result, forwards/sends the email to one of two shared mailboxes
Loops through the original attachments
Saves each attachment to SharePoint
Retrieves the file again from SharePoint
Re-attaches the file to a new email using Send email from shared mailbox (V2)

Everything works functionally, but the re-attached files (PDFs and images) are corrupted

Flow details

Inside an Apply to each loop:

Get attachment (V2) (Office 365 Outlook)
Create file (SharePoint)
Get file content (SharePoint)
Append to an array variable (spAttachments)
Use that array in Send email from shared mailbox (V2) → Attachments

The problem

The attachments arrive at the destination mailbox but are corrupted (PDFs cannot be opened, images are invalid).

To debug, I added a Compose action after Get file content.

The output starts with:

So Get file content is returning raw file content (PDF structure), not Base64.

However, the Outlook "Send email (V2)" connector expects:

What I already tried

Passing body('Get_file_content') directly → corrupted
Using base64(body('Get_file_content')) → still corrupted
Using $content property (when available) → still corrupted
Bypassing SharePoint and directly using:

outputs('Get_attachment_(V2)')?['body/contentBytes'] → still corrupted
Building the attachment object using: addProperty(json('{}'), ...)
Using JSON(concat()) method
Using direct object syntax in the array

Flow runs successfully. No runtime errors. Attachments just arrive broken

Key observation

From Compose output:

Get file content clearly returns raw binary (PDF text structure), not Base64.

Even when converting with base64() before assigning to ContentBytes, the attachment still arrives corrupted

Questions

Is there a known issue when re-attaching files retrieved via SharePoint Get file content?
Should base64ToBinary() be used before saving to SharePoint and then $content retrieved?
Is there a known size/encoding limitation with array variables and large Base64 strings? I just send normal seized pdfs and pictures so far
Is it recommended to use Forward email (V2) instead of rebuilding attachments? - which was also not working for me...
Is there a specific way the Outlook connector expects attachment objects when using shared mailboxes?

Expected behavior

Original attachment → saved to SharePoint → retrieved → reattached → identical file.

Currently: file content is altered/corrupted somewhere in the process

If anyone has a proven pattern for:

Email attachment → SharePoint → retrieve → reattach → Send email (V2)

without corruption, I would greatly appreciate it.

Thanks in advance.

Hello @SR-13022228-0,

Please try this approach. I understand that you have uploaded the attachment to a document library. When you use the Get file content action, it already returns the file in Base64 format, so there is no need to encode it again.

Please give this a try.

{
  "ContentBytes": @{body('Get_file_content')},
  "Name": @{items('Apply_to_each_5')?['{FilenameWithExtension}']}
}

Reference blog:

https://automations365.com/power-automate-get-attachments-in-sharepoint-library-and-send-to-email/

https://learn.microsoft.com/en-us/microsoft-365/community/power-automate-send-sharepoint-files-as-attachments

If this response resolves your issue, please mark it as the Verified Answer so it can help other community members as well.

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