Good day All,

I have a concerning error on hand, my PABX is no longer sending emails via Office365.
It has been working for a few months, however it just stopped.
Has anyone else experienced this as well?

See error below.

Connecting to server smtp.office365.com on port 587

<-- 220 BL0PR02CA0090.outlook.office365.com Microsoft ESMTP MAIL Service ready at Wed, 22 Jul 2020 19:51:15 +0000

--> EHLO UC80.epygi-config.loc

<-- 220 BL0PR02CA0090.outlook.office365.com Microsoft ESMTP MAIL Service ready at Wed, 22 Jul 2020 19:51:15 +0000
250-BL0PR02CA0090.outlook.office365.com Hello [24.172.77.170]
250-SIZE 157286400
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-STARTTLS
250-8BITMIME
250-BINARYMIME
250-CHUNKING
250 SMTPUTF8
--> STARTTLS
<-- 220 2.0.0 SMTP server ready


--> EHLO UC80.epygi-config.loc

<-- 250-BL0PR02CA0090.outlook.office365.com Hello [24.172.77.170]
250-SIZE 157286400
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-AUTH LOGIN XOAUTH2
250-8BITMIME
250-BINARYMIME
250-CHUNKING
250 SMTPUTF8
--> AUTH LOGIN
<-- 334 UGFzc3dvcmQ6

--> NDMzNUNMVG5jIQ==

email: FATAL: Smtp error: 334 UGFzc3dvcmQ6
535 5.7.3 Authentication unsuccessful [BL0PR02CA0090.namprd02.prod.outlook.com]