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Helper I
Helper I

Custom API File Type

 I'm developing an app connection with Microsoft Flow.

My app is a document management app (created by me) and the goal is foir example to upload a file from my app to One Drive, using flows.


I have an action that consists when an email is flagged in outlook its attachement is added to azure storage (linked with my app).FlowFlow

The parameters are : Raw Body inputs (FileStream with the attachement content) , Doc_Name (FIle name) , Cont_ID (Reference to the folder from azure where the file's gonna be saved).


THis flow retrives the error 400 (has you can see in the images).


I think it's because the Content type in my app is not the correct one. (I'm using FileStream) ErrorError

Community Support
Community Support

Hi @Fvamaro,


OneDrive has the corresponding Create File Action.

If here you would like to save Email Attachments into OneDrive folder, then take a look at the template:

Save new Email Attachment  to any folder in OneDrive for Business


Besides, you may take a try with the template above, and then change the content type accordingly.

By the way, the Name Dynamic content from the attachment should contain the file type.




Community Support Team _ Michael Shao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Hi @v-micsh-msft,


The point is: I'm integrating flow with an app I've developed.

One of the actions I want the connector to be able to do is get an attachement from a flagged email and add it to my personal storage using Microsoft FLow ( as you can see int the first image).

For this I have to build a method in my asp.NET project to receive the file from the email.


The issue is that I do not know for sure what kind of variable is the content atribute (where the content of the attachement is).


In Other words: (Simplifying the problem)

What I want to know is how Flow connectores exchange files between each other.

When an attachement is saved form Outlook to OneDrive how the information is sent?
How the Content attribute (dynamic value from attachement) is sent and received from Outlook to OneDrive.



Filipe Amaro

Hi @Fvamaro,


The attachments in Microsoft Outlook is stored as an array, you may take a look at the following thread as a reference:

Post File via HTTP




Community Support Team _ Michael Shao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Thank you @v-micsh-msft,

I think it will be helpful, if it is I will accept it as a solution.




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