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.NET Core Azure Function to send SMTP email to/with Office 365

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Created to send email via an Azure Function, using .NET Core, through Office 365.

Setup

  • Clone repo
  • Publish Azure Function to Azure Functions
  • Get Azure Function's Function Key - required to access function

To Use

  • Edit data.json, found in root of this project, with your own values:

      {
    "toEmail": "johnsmith@contoso.com",
    "textSubject": "testing Azure function",
    "textBody": "hello body",
    "fromAccountEmail": "<REPLACE-WITH-YOUR-0365-ACCOUNT>@microsoft.com",
    "fromAccountPassword": "<REPLACE-WITH-YOUR-0365-ACCOUNT-PASSWORD>",
    "smtpHost": "smtp.office365.com",
    "smtpPort": "587",
    "fromAccountDomain": "microsoft.com"
  }

  • Example HTTP command:

    POST /api/sendemail?code=<REPLACE_WITH-YOUR-FUNCTION-RESOURCE-FUNCTION-KEY> HTTP/1.1
  Host: <REPLACE_WITH-YOUR-FUNCTION-RESOURCE-NAME>.azurewebsites.net
  Content-Type: application/json
  Cache-Control: no-cache

  {
  	toEmail: "johnsmith@contoso.com",
  	textSubject: "testing Azure function",
  	textBody: "hello body",
  	fromAccountEmail:"<REPLACE-WITH-YOUR-0365-ACCOUNT>@microsoft.com",
  	fromAccountPassword:"<REPLACE-WITH-YOUR-0365-ACCOUNT-PASSWORD>"
  	smtpHost: "smtp.office365.com"
  	smtpPort: "587"
  }

    Use the table to understand the replacements:

    Term Replacement
    <REPLACE_WITH-YOUR-FUNCTION-RESOURCE-NAME> String: your Azure Function resource name
    <REPLACE_WITH-YOUR-FUNCTION-RESOURCE-FUNCTION-KEY> String: your Azure Function resource's function key. The function returns auth error if the key is not sent.
    <REPLACE-WITH-YOUR-0365-ACCOUNT> String: your 0365 User account.
    <REPLACE-WITH-YOUR-0365-ACCOUNT-PASSWORD> String: your 0365 User account password.

    Execute the cURL command from a bash terminal in the root of this project so that the data.json file doesn't need any path resolution. Make sure to change the following command to use your Azure Function name and key

      curl -v -X POST \
  -H 'Content-type: application/json' \
  -d @data.json 'https://<REPLACE_WITH-YOUR-FUNCTION-RESOURCE-NAME>.azurewebsites.net/api/sendemail?code=<REPLACE_WITH-YOUR-FUNCTION-RESOURCE-FUNCTION-KEY>'

Caveats

This Azure function can't be successfully run from a local machine due to the restrictions of the SMTP client usage from Office 365. See Documentation references for details.

Watch Azure Function Log stream

When you test this Azure-deployed function, use the Azure portal to watch this Azure Function's Log stream. Successful logging output looks something like:

2021-07-26T16:00:30.000 [Information] Executing 'SendEmail' (Reason='This function was programmatically called via the host APIs.', Id=dde6166f-8833-4a7f-b40d-c9c7d2fc48ca)
2021-07-26T16:00:30.000 [Information] sendemail
2021-07-26T16:00:30.001 [Information] sendemail received data
2021-07-26T16:00:30.001 [Information] sendemail fetched variables
2021-07-26T16:00:30.004 [Information] sendemail got variables
2021-07-26T16:00:30.005 [Information] sendemail client constructed
2021-07-26T16:00:30.005 [Information] sendemail mail constructed
2021-07-26T16:00:31.373 [Information] sendemail mail sent
2021-07-26T16:00:31.374 [Information] Executed 'SendEmail' (Succeeded, Id=dde6166f-8833-4a7f-b40d-c9c7d2fc48ca, Duration=1374ms)

Documentation references

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