Outlook email error

[steelies]

As it looked as though my email had been hacked I changed my password.  I logged into Postbox and everything seemed to be working OK.  I then tried to send email via Outlook on Mac but recevied the following message:

5.7.8 [TPG-A02] Authentication denied. User steelies@tpg.com.au is banned from using SMTP AUTH due to previous abuse

TPG online chat wasn't able to help because Post Office was working fine and they said they couldn't really help with third party programs.  Microsoft online chat services were next to useless and have been unable to help me with a solution.  Note that I can receive messages via Outlook on Mac but can't send them.

Has anyone had this problem and, if so, can you help me fix my settings to sort this out.  Thanks!

[david64]

Whereabouts did you change your password? What is "Postbox"?

Searching on internet, 578 relates to failure with user credentials: userid, password.

As a test, change your password back as it was, wherever you changed it, then see what happens.

Your password may have to match in more than one place: e.g. router when you connect to TPG internet; mail client on your computer. 

[steelies]

Hi, David. I  changed it originally in Post Office then proceeded to change it in my Outlook so that the two matched.  Funny thing is I can receive emails but just cannot send without that message coming up.  Would you suggest that I change everything back then starting with Post Office and then through Outlook itself?

[david64]

Did you change it via the "Change your Password" in "Your Account"? Instructions there.

There's a note re adsl, but I'd change password in the router anyhow in case the connection drops.

If that doesn't help, change it back to the start.

[steelies]

Yes, that's where I changed my Password.  I'm afraid I don't understand the rest of your message.  Change what back to where?

[david64]

Change your password back to your hacked password in each place you have changed it so they all match.

There's My Account, Post Office, your Outlook client, your router (anywhere else?). Then let it settle down.

Then do it according to the instructions. There might be a limit on the number of times you can do this each day.