Configuring Gmail results in 'Failed to issue MAIL command: 555 5.5.2 Syntax error'

[KelchtermansBram]

Description

I tried configuring my Google Workspace & generic gmail account in the Gitea mailer config by following the documentation provided at https://docs.gitea.com/administration/email-setup

However, when sending a test email I get the following error:
failed to issue MAIL command: 555 5.5.2 Syntax error, cannot decode response. For more information, go to 5.5.2 https://support.google.com/a/answer/3221692 and review RFC 5321 5.5.2 specifications. 4fb4d7f45d1cf-64068f74a56sm1990428a12.15 - gsmtp

Using the exact same credentials in another application works as a charm.

Things I've tried

• Try smtp+starttls and smtps
• Use both a generic gmail account and a google workspace account
• Changing the default name (Gitea: Git with a cup of tea) to my own name and/or email
• Manually send an email by using swaks from the host machine (Gitea is running in a docker on that machine)

Am I doing something wrong or is this a global issue?

Gitea Version

1.25.0

Can you reproduce the bug on the Gitea demo site?

No

Log Gist

No response

Screenshots

No response

Git Version

2.49.1

Operating System

Ubuntu

How are you running Gitea?

Selfhosted with Docker

Database

None

[dangjinghao]

Hi, did you test this in Gitea 1.24.7? Based on my similar issue #35788, it works. If so, it's possible that the change is related to the go-mail dependency update in 1.25.0.

[dangjinghao]

Would you mind testing this again following the steps in my comment? I think it would be related.

[lunny]

Created an issue upstream wneessen/go-mail#504

[wneessen]

Please see wneessen/go-mail#504 (comment)

TL;DR:
This is an issue with the Gitea implementation, not a go-mail bug. Gitea uses the low-level SMTP package of go-mail, which had a breaking change (to fix a vulnerability) in the 0.7.1 (and corresponding 0.7.2) release. Gitea either needs to adjust their code for the from address handling when talking to the SMTP server or use the go-mail Client instead, which would make the change for the underlying SMTP package transparent to the user.