"Failure sending mail" error sending emails

Hello, i am having issues i am hoping someone has had before when sending mail from QLM today and I keep seeing a "Failure sending mail" message in the logs and on the screen when I test the smtp server.
 
I had the change the password for the account being used as the old password had expired and since then it won’t send the emails.
 
I have verified that all credentials and config are correct and I have also ran a test app using those same credentials and it can send the email ok so it is not firewall or account related.
 
I’ve also changed the server to smtp.gmail.com and used my gmail credentials and it is still not working.

Here is an error from the event logs:
 
Sending SMTP email from <email_address@company.com> to <user_email_address@company.com> using server smtp.office365.com and logonUser <email_address@company.com>.
Setting email body - HtmlFormat: True
Sending message
Exception: Failure sending mail.

The error does not give me enough information to figure out what is wrong with it. Does anyone have any ideas on what to look for to resolve this?

Thanks