smtp tool cant not work when Send emails to multiple people #100

New Issue

2026-02-22T17:18:40-05:00

yindo commented

2026-02-22 17:18:40 -05:00

Originally created by @agoraphobiaX on GitHub (Jun 15, 2025).

Self Checks

This is only for bug report, if you would like to ask a question, please head to Discussions.
I have searched for existing issues search for existing issues, including closed ones.
I confirm that I am using English to submit this report (我已阅读并同意 Language Policy).
[FOR CHINESE USERS] 请务必使用英文提交 Issue，否则会被关闭。谢谢！:)
Please do not modify this template :) and fill in all the required fields.

Dify version

1.4.1

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

smtp tool cant not work when Send emails to multiple people。

Failed to transform tool message: PluginInvokeError: {"args":{},"error_type":"ValidationError","message":"1 validation error for SendEmailToolParameters\nsender_address\n Field required [type=missing, input_value={'smtp_server': 'smtp.yn....], 'bcc_recipients': []}, input_type=dict]\n For further information visit https://errors.pydantic.dev/2.8/v/missing"}

✔️ Expected Behavior

No response

❌ Actual Behavior

No response

Originally created by @agoraphobiaX on GitHub (Jun 15, 2025). ### Self Checks - [x] This is only for bug report, if you would like to ask a question, please head to [Discussions](https://github.com/langgenius/dify/discussions/categories/general). - [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones. - [x] I confirm that I am using English to submit this report (我已阅读并同意 [Language Policy](https://github.com/langgenius/dify/issues/1542)). - [x] [FOR CHINESE USERS] 请务必使用英文提交 Issue，否则会被关闭。谢谢！:) - [x] Please do not modify this template :) and fill in all the required fields. ### Dify version 1.4.1 ### Cloud or Self Hosted Self Hosted (Docker) ### Steps to reproduce smtp tool cant not work when Send emails to multiple people。 Failed to transform tool message: PluginInvokeError: {"args":{},"error_type":"ValidationError","message":"1 validation error for SendEmailToolParameters\nsender_address\n Field required [type=missing, input_value={'smtp_server': 'smtp.yn....], 'bcc_recipients': []}, input_type=dict]\n For further information visit https://errors.pydantic.dev/2.8/v/missing"} ### ✔️ Expected Behavior _No response_ ### ❌ Actual Behavior _No response_

yindo closed this issue

2026-02-22 17:18:40 -05:00

yindo commented

2026-02-22 17:18:40 -05:00

@dosubot[bot] commented on GitHub (Jun 15, 2025):

The error happens because the required sender_address field is missing from the parameters when sending to multiple recipients. This is likely due to how the parameters are constructed and passed to the SMTP tool—if sender_address is omitted or set to None, Pydantic validation fails and you get this error.

To resolve this, make sure that sender_address is always included in the tool parameters, regardless of how many recipients you have. Double-check your workflow or plugin configuration to ensure sender_address is set and not accidentally dropped when building the parameter dictionary for multi-recipient sends. Also, confirm that your MAIL_DEFAULT_SEND_FROM is set in your environment or config, as this is used as a fallback if sender_address is not provided directly (source).

If you’re customizing the workflow, review the parameter generation logic to ensure sender_address is always present, especially in multi-recipient scenarios (source). This should resolve the validation error and allow emails to be sent to multiple people.

To reply, just mention @dosu.

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}

@dosubot[bot] commented on GitHub (Jun 15, 2025):  The error happens because the required sender_address field is missing from the parameters when sending to multiple recipients. This is likely due to how the parameters are constructed and passed to the SMTP tool—if sender_address is omitted or set to None, Pydantic validation fails and you get this error. To resolve this, make sure that sender_address is always included in the tool parameters, regardless of how many recipients you have. Double-check your workflow or plugin configuration to ensure sender_address is set and not accidentally dropped when building the parameter dictionary for multi-recipient sends. Also, confirm that your MAIL_DEFAULT_SEND_FROM is set in your environment or config, as this is used as a fallback if sender_address is not provided directly ([source](https://github.com/langgenius/dify/blob/d587480a3e4c38333860331c3684ddc6f771ca01/api/extensions/ext_mail.py)). If you’re customizing the workflow, review the parameter generation logic to ensure sender_address is always present, especially in multi-recipient scenarios ([source](https://github.com/langgenius/dify/blob/d587480a3e4c38333860331c3684ddc6f771ca01/api/core/workflow/nodes/tool/tool_node.py)). This should resolve the validation error and allow emails to be sent to multiple people.  *To reply, just mention [@dosu](https://go.dosu.dev/dosubot).* --- <sup>How did I do? [Good](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=great_response) | [Irrelevant](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=irrelevant_answer) | [Incorrect](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=incorrect_sources) | [Verbose](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=too_verbose) | [Hallucination](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=hallucination) | [Report 🐛](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=bug_report) | [Other](https://app.dosu.dev/response-feedback/cab9cd78-c839-4074-bb0b-877c0a851219?feedback_type=other)</sup>  [![Join Discord](https://img.shields.io/badge/join-5865F2?logo=discord&logoColor=white&label=)](https://go.dosu.dev/discord-bot) [![Share on X](https://img.shields.io/badge/X-share-black)](https://twitter.com/intent/tweet?text=%40dosu_ai%20helped%20me%20solve%20this%20issue!&url=https%3A//github.com/langgenius/dify/issues/21034)

yindo commented

2026-02-22 17:18:40 -05:00

@agoraphobiaX commented on GitHub (Jun 15, 2025):

how to make sure that sender_address is always included in the tool parameters?
becaues when i send mail to one person it works.

@agoraphobiaX commented on GitHub (Jun 15, 2025): how to make sure that sender_address is always included in the tool parameters? becaues when i send mail to one person it works.

yindo commented

2026-02-22 17:18:40 -05:00

@crazywoola commented on GitHub (Feb 3, 2026):

Hi @agoraphobiaX, thanks for opening this issue.

Why this is being closed

Dify issue tracking requires English-only issue title and description for consistent collaboration.

Next steps

Please open a new issue in English and include clear details so maintainers can help efficiently.

Thanks for understanding and for your support.

@crazywoola commented on GitHub (Feb 3, 2026): Hi @agoraphobiaX, thanks for opening this issue. ### Why this is being closed Dify issue tracking requires English-only issue title and description for consistent collaboration. ### Next steps Please open a new issue in English and include clear details so maintainers can help efficiently. Thanks for understanding and for your support.

yindo referenced this issue

2026-02-22 17:39:44 -05:00

[PR #330] [MERGED] feat(pull_request_template): add fields for author, name, and repository url #820

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Reference: langgenius/dify-plugins#100