Failed to send test email in Gitea 1.25.0

[dangjinghao]

Description

After updating to Gitea 1.25.0, the test email fails to send with the error:

failed to issue MAIL command: 502 Invalid input from xxxIPxxx to newxmesmtplogicsvrszb20-1.qq.com.

I temporary create a Gitea 1.24.7 website with same [mailer] content, and try to send test email again, it just works.

Configuration:

[mailer]
ENABLED = true
FROM = xxx@qq.com
SMTP_ADDR = smtp.qq.com
SMTP_PORT = 465
USER = xxx@qq.com
PASSWD = xxx

Neither SMTP_PORT = 465(smtps) nor SMTP_PORT = 587(smtp+starttls) doesn't work.

Gitea Version

1.25.0

Can you reproduce the bug on the Gitea demo site?

No

Log Gist

No response

Screenshots

1.25.0:

1.24.7 with same mailer configuration:

Git Version

No response

Operating System

No response

How are you running Gitea?

1.25.0: docker image: gitea/gitea:latest

1.24.7: download from releases page

Database

SQLite

[KazzmanK]

it works for me. Tried test email - received it fine

[silverwind]

The only thing I can think of that could be related is the recent go-mail upgrades that were done:

https://github.com/wneessen/go-mail/releases

[dangjinghao]

Test completed. This confirms breaking changes in go-mail v0.7.1. v0.7.0 works fine.

See the diff here.

Unfortunately, I am too busy to investigate why.

I've created a patch at ef90bef using go-mail v0.7.0 for testing.

I can't upload the gitea.tgz file at the moment. Please download it for testing from my old Gitea fork's releases page.

Critical: Use a Test Instance for Verification

To prevent any potential impact on your data, please do not use the production database. Because Gitea may update the schema version.

It is strongly recommended to create a new, isolated Gitea instance specifically for this purpose.

Test Procedure:
According to my findings, no modifications to the mailer section configuration are required. Simply run my patched Gitea binary and attempt to send a test email. It should be sent successfully as expected.

[lunny]

It may be caused by the upgrade of wneessen/go-mail from v0.6.2 to v0.7.2.

[lunny]

This should be resolved by #35816