Email smtp error🤣

[bigbugcc]

When I change the smtp configuration to Aliyun mailbox and send a test email, it prompts [ERROR] SMTP client error: internal client error: Unrecognized challenge, the following is the detailed log when I test it.

[2024-10-18 00:30:05.081][lettre::transport::smtp::client::async_connection][DEBUG] << 220 smtp.aliyun-inc.com MX AliMail Server<CRLF>
[2024-10-18 00:30:05.082][lettre::transport::smtp::client::async_connection][DEBUG] Wrote: EHLO 78367f60555d<CRLF>
[2024-10-18 00:30:05.121][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>
[2024-10-18 00:30:05.121][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>250-8BITMIME<CRLF>
[2024-10-18 00:30:05.121][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>250-8BITMIME<CRLF>250-AUTH=PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>
[2024-10-18 00:30:05.121][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>250-8BITMIME<CRLF>250-AUTH=PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>250-AUTH PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>
[2024-10-18 00:30:05.122][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>250-8BITMIME<CRLF>250-AUTH=PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>250-AUTH PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>250-PIPELINING<CRLF>
[2024-10-18 00:30:05.122][lettre::transport::smtp::client::async_connection][DEBUG] << 250-smtp.aliyun-inc.com<CRLF>250-8BITMIME<CRLF>250-AUTH=PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>250-AUTH PLAIN LOGIN XOAUTH2 XALIOAUTH<CRLF>250-PIPELINING<CRLF>250 DSN<CRLF>
[2024-10-18 00:30:05.122][lettre::transport::smtp::client::async_connection][DEBUG] server smtp.aliyun-inc.com with {EightBitMime, Authentication(Login), Authentication(Xoauth2), Authentication(Plain)}
[2024-10-18 00:30:05.122][lettre::transport::smtp::client::async_connection][DEBUG] Wrote: AUTH LOGIN<CRLF>
[2024-10-18 00:30:05.161][lettre::transport::smtp::client::async_connection][DEBUG] << 334 dXNlcm5hbWU6<CRLF>
[2024-10-18 00:30:05.161][lettre::transport::smtp::commands][DEBUG] auth encoded challenge: dXNlcm5hbWU6
[2024-10-18 00:30:05.161][lettre::transport::smtp::commands][DEBUG] auth decoded challenge: username:
[2024-10-18 00:30:05.161][vaultwarden::mail][ERROR] SMTP client error: internal client error: Unrecognized challenge

config.json

......
  "_enable_smtp": true,
  "use_sendmail": false,
  "smtp_host": "smtp.qiye.aliyun.com",
  "smtp_security": "force_tls",
  "smtp_port": 465,
  "smtp_from": "xxx@xxx.com",
  "smtp_from_name": "Vaultwarden",
  "smtp_username": "xxx@xxx.com",
  "smtp_password": "xqxxxxxxxxxxx",
  "smtp_auth_mechanism": "Login",
  "smtp_timeout": 15,
  "smtp_embed_images": true,
  "smtp_accept_invalid_certs": false,
  "smtp_accept_invalid_hostnames": false,
  "_enable_email_2fa": true,
  "email_token_size": 6,
  "email_expiration_time": 600,
  "email_attempts_limit": 3,
  "email_2fa_enforce_on_verified_invite": true,
  "email_2fa_auto_fallback": false
......

Test telnet outgoing mail on the server (using the same smtp configuration) can be sent normally.

[BlackDex]

Your mail server is not adhering to standards.
It should send Username: and not username: note the capital U.
And after that it should also send Password: with a capital P.

[BlackDex]

You might want to try Plain instead of Login and see if that solves your problem.

[bigbugcc]

Thank you for your reply, the problem was indeed as you said, I solved the problem by changing the login to Plain, thank you very much Have a nice day!

[BlackDex]

@bigbugcc, Since we do want to have this working more inclusively, and there seem to be specific RFC regarding what the server should return the developer of Lettre created a patch which should let Login work with the value your provider returns.

It would be very cool if you could test this version if it works with Login instead of Plain.

To this this, you should change the container image to use a custom build version in my personal repo which has this fix.

I have pushed these containers to my docker hub and quay.io repo's.

Docker: https://hub.docker.com/repository/docker/blackdex/vaultwarden/tags

• Debian: docker.io/blackdex/vaultwarden:lettre
• Alpine: docker.io/blackdex/vaultwarden:lettre-alpine

Quay: https://quay.io/repository/blackdex/vaultwarden?tab=tags

• Debian: quay.io/blackdex/vaultwarden:lettre
• Alpine: quay.io/blackdex/vaultwarden:lettre-alpine

[bigbugcc]

Sorry😅, I've given up on that vendor's email service for a number of other reasons.