# OAuth2 Client - Email Test Fails - Syntax Error 555-5.5.2

**URL:** <https://forum.inductiveautomation.com/t/oauth2-client-email-test-fails-syntax-error-555-5-5-2/93550>\
**Category:** Ignition\
**Created:** [July 22, 2024, 5:07pm UTC](https://forum.inductiveautomation.com/t/oauth2-client-email-test-fails-syntax-error-555-5-5-2/93550 "2024-07-22T17:07:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![edward.fowler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/edward.fowler/32/24179_2.png) [@edward.fowler](https://forum.inductiveautomation.com/u/edward.fowler)\
**Post date:** [July 22, 2024, 5:07pm UTC](https://forum.inductiveautomation.com/t/oauth2-client-email-test-fails-syntax-error-555-5-5-2/93550/1 "2024-07-22T17:07:27Z")

</div>

v8.1.41  
The OAuth2 client authorization test is successful.  
The OAuth2 client token test is successful.  
Test Email response:

> javax.mail.AuthenticationFailedException: 555-5.5.2 Syntax error, goodbye. For more information, go to  
> 555-5.5.2 [About SMTP error messages - Google Workspace Admin Help](https://support.google.com/a/answer/3221692) and review RFC 5321  
> 555 5.5.2 specifications. 46e09a7af769-708f60a5325sm1569445a34.6 - gsmtp

RFC 5321, from 2008:  
4.1.1.11

> If the server SMTP does not recognize or cannot implement one or more of the parameters associated with a particular MAIL FROM or RCPT TO command, it will return code 555.

The syntax error is thrown when testing with from/to addresses _[foo@bar.com](mailto:foo@bar.com)_  
Testing email with a Classic SMTP profile and the same address is successful.  
The RFC suggest formatting the to/from addresses as _[foo@bar.com](mailto:foo@bar.com)_ which doesn't work, the same syntax error is thrown.

Has anyone encountered this issue?

Thank you.