# SMTP client error: internal client error: No compatible authentication mechanism was found

**URL:** <https://vaultwarden.discourse.group/t/smtp-client-error-internal-client-error-no-compatible-authentication-mechanism-was-found/3925>\
**Category:** Uncategorized\
**Created:** [August 25, 2024, 11:36am UTC](https://vaultwarden.discourse.group/t/smtp-client-error-internal-client-error-no-compatible-authentication-mechanism-was-found/3925 "2024-08-25T11:36:44Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Keplertech](https://avatars.discourse-cdn.com/v4/letter/k/e9c0ed/32.png) [@Keplertech](https://vaultwarden.discourse.group/u/Keplertech)\
**Post date:** [August 25, 2024, 11:36am UTC](https://vaultwarden.discourse.group/t/smtp-client-error-internal-client-error-no-compatible-authentication-mechanism-was-found/3925/1 "2024-08-25T11:36:44Z")

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i’ve this problem SMTP client error: internal client error: No compatible authentication mechanism was found  
when i try to send an email test i got an error : ERROR sending SMTP test email 400 Bad request Unknown  
and when i try to add a member i got this error SMTP client error: internal client error: No compatible authentication mechanism was found

 ![vaulterror](https://global.discourse-cdn.com/free1/uploads/vaultwarden/original/2X/d/dd2cb72ffcd10bf0c5d51d98587013eb0c4b3faa.png)

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**Author:** ![stefan0xC](https://yyz2.discourse-cdn.com/free1/user_avatar/vaultwarden.discourse.group/stefan0xc/32/1765_2.png) [@stefan0xC](https://vaultwarden.discourse.group/u/stefan0xC)\
**Post date:** [August 25, 2024, 12:00pm UTC](https://vaultwarden.discourse.group/t/smtp-client-error-internal-client-error-no-compatible-authentication-mechanism-was-found/3925/2 "2024-08-25T12:00:50Z")

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We don’t support oauth2 (yet) and if Microsoft doesn’t support other authentication mechanisms you’ll have to switch to a different provider or use an email proxy for this as suggested in this thread

> **[OAuth SMTP support · dani-garcia/vaultwarden · Discussion #4518](https://github.com/dani-garcia/vaultwarden/discussions/4518#discussioncomment-9211666)**
>
> I've just spent several hours trying to set up Vaultwarden SMTP to work with my Microsoft 365 service. Tbf it was mostly due to Microsoft's settings being spread across many websites, docs etc., bu...