Send Grid Connector - Send Email (Multiple Attachments)

In the scenario when we have a logic app with O365 Trigger - when a new email arrives, and the email comes with multiple attachments; there is a current limitation in Send Grid connector -Send Email V4; where we cannot use the attachments array to send the received attachments all at once in one email.

The below logic app shows the limitation scenario:

If we used the above structure, the send grid action will fail with the below error:

For Send Grid Connector - Send email (V4); we can manually add the attachments using the individual attachment form; as below:

But this will cause each attachment to be sent in a separate email (due to the for each); which is not the desired target of the logic app.

By looking into code view, of the attachment array structure; when adding the attachment manually; we find it to be in the below structure:

 "attachments": [

                                    {

                                        "content": "@{items('For_each')?['contentBytes']}",

                                        "contenttype": "@items('For_each')?['contentType']",

                                        "filename": "@items('For_each')?['name']"

                                    }

                                ]

 

So, the work around for this limitation, is to build the above attachments array within the logic app, and pass it as an attachment array to the Send Grid action; as below:

Note: The attachment content from the dynamic content is "@{base64ToString(items('For_each')?['contentBytes'])}"; using it like this causes the send grid action to fail with error:

  {

                "message": "The attachment content must be base64 encoded.",

                "field": "attachments.0.content",

                "help": "http://sendgrid.com/docs/API_Reference/Web_API_v3/Mail/errors.html#message.attachments.content"

            }

 

So, we need to switch to Code view, and update the Append Array action to have the below body (we removed the base64ToString expression) :

 {

                                "content": "@{items('For_each')?['contentBytes']}",

                                "contenttype": "@{items('For_each')?['contentType']}",

                                "filename": "@{items('For_each')?['name']}"

                            }

 

Also, the For Each parallelism need to be set to 1; in order to avoid incorrect variable assignments.

 

After having the array ready, we can pass it directly to the send grid action as below:

 

Below is the Full Logic App structure:

 

By this, we can send all received attachment (from the O365) to the Send Grid action; in one execution.