I’m struggling to send emails with multiple attachents in Outlook. The standard Send Email node works but I need to hard code the number of attachments. Ideally I would just send a message with 0, 1 or multiple attachments. I’m running into errors in the create draft or add attachment nodes that would allow this behavior, see my other post below.
It seems the “Outlook/Message/Send” node behaves different than the Outlook/Draft/Create node. When I add an attachment, the draft node fails.
{
"errorMessage": "were unable to deserialize ",
"errorDetails": {
"rawErrorMessage": [
"400 - {\"error\":{\"code\":\"UnableToDeserializePostBody\",\"message\":\"were unable to deserialize \"}}"
],
"httpCode": "400"
},
"n8nDetails": {
"nodeName": "Create a draft: Fails!",
"nodeType": "n8n-nodes-base.microsoftOutlook",
"nodeVersion": 2,
"resource": "draft",
"operation": "create",
"itemIndex": 0,
"time": "12/12/2025, 13:15:47",
"n8nVersion": "2.0.1 (Cloud)",
"binaryDataMode": "filesystem",
"stackTrace": [
"NodeApiError: were unable to deserialize ",
" at ExecuteContext.requestWithAuthentication (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/node-execution-context/utils/request-helper-functions.ts:1498:10)",
" at processTicksAndRejections (node:internal/process/task_queues:105:5)",
" at ExecuteContext.requestWithAuthentication (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/node-execution-context/utils/request-helper-functions.ts:1798:11)",
" at ExecuteContext.microsoftApiRequest (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@[email protected]_asn1.js@5_8da18263ca0574b0db58d4fefd8173ce/node_modules/n8n-nodes-base/nodes/Microsoft/Outlook/v2/transport/index.ts:52:10)",
" at ExecuteContext.execute (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@[email protected]_asn1.js@5_8da18263ca0574b0db58d4fefd8173ce/node_modules/n8n-nodes-base/nodes/Microsoft/Outlook/v2/actions/draft/create.operation.ts:252:23)",
" at ExecuteContext.router (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@[email protected]_asn1.js@5_8da18263ca0574b0db58d4fefd8173ce/node_modules/n8n-nodes-base/nodes/Microsoft/Outlook/v2/actions/router.ts:51:21)",
" at ExecuteContext.execute (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@[email protected]_asn1.js@5_8da18263ca0574b0db58d4fefd8173ce/node_modules/n8n-nodes-base/nodes/Microsoft/Outlook/v2/MicrosoftOutlookV2.node.ts:28:10)",
" at WorkflowExecute.executeNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1045:8)",
" at WorkflowExecute.runNode (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1226:11)",
" at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:1662:27",
" at /usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-core@file+packages+core_@[email protected]_@[email protected]_ec37920eb95917b28efaa783206b20f3/node_modules/n8n-core/src/execution-engine/workflow-execute.ts:2274:11"
]
}
}
The same error occurs with the add attachment node. My hypothesis is that n8n sends the wrong payload to the Microsoft Graph API when using the draft node. The same error occurs in the add attachment node.
I’m getting an error in the code node: Error: No attachments found at VmCodeWrapper (evalmachine.<anonymous>:3:9) at evalmachine.<anonymous>:14:2 at Script.runInContext (node:vm:149:12) at runInContext (node:vm:301:6) at result (/opt/runners/task-runner-javascript/dist/js-task-runner/js-task-runner.js:185:61) at new Promise (<anonymous>) at JsTaskRunner.runForAllItems (/opt/runners/task-runner-javascript/dist/js-task-runner/js-task-runner.js:178:34) at JsTaskRunner.executeTask (/opt/runners/task-runner-javascript/dist/js-task-runner/js-task-runner.js:128:26) at process.processTicksAndRejections (node:internal/process/task_queues:105:5) at async Object.waitingForSettings (/opt/runners/task-runner-javascript/dist/task-runner.js:256:17)
