In one of application, Email alerts are sent using SQL sp_send_dbmail stored procedure. Email alerts were working properly, but suddenly noticed email alerts are not received.
To troubleshoot the issue, first I checked the msdb.dbo.sysmail_event_log table using the below query.
SELECT log_id, event_type, log_date, description, process_id, mailitem_id, account_id, last_mod_date, last_mod_user
FROM
msdb.dbo.sysmail_event_log
ORDER BY
log_date DESC
If there is any error, you should see records with the event_type value as error.
In my case there are records with event_type value as error, and the description value for those records is same as below
The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 3 (2018-02-01T10:41:27). Exception Message: Cannot send mails to mail server. (The SMTP server requires a secure connection or the client was not authenticated. The server response was: Authentication required). )
To troubleshoot the issue, first I checked the msdb.dbo.sysmail_event_log table using the below query.
SELECT log_id, event_type, log_date, description, process_id, mailitem_id, account_id, last_mod_date, last_mod_user
FROM
msdb.dbo.sysmail_event_log
ORDER BY
log_date DESC
If there is any error, you should see records with the event_type value as error.
In my case there are records with event_type value as error, and the description value for those records is same as below
The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 3 (2018-02-01T10:41:27). Exception Message: Cannot send mails to mail server. (The SMTP server requires a secure connection or the client was not authenticated. The server response was: Authentication required). )
As per the error description, it should be due to the sender account issue.
The reason was the Sender password is changed and it is not updated in the Database Mail configurations. Once I updated the password in the Database Mail configurations, email alerts started to work properly.
