Unable to send out emails through my admin programe


New Email

I have a btconnect e-mail address which I use from my office, all was working fine till BT changed their pop and smtp settings back in Oct/Nov time from btconnect to outlook. This has now affected my admin system which is hosted third party by Titan (I can log into the admin system from anywhere) the system is used to send out confirmations and reminders to my customers that have e-mail addresses.

When I have invoiced the client and click to send an e-mail I get error message

The SMTP server requires a secure connection or the client was not authenticated. The server response was 5.7.1 Client was not authenticated.

My actual e-mail that I send out direct from windows live mail or outlook is sending and receiving just fine so I know the settings are correct. I have deleted the accounts and re set them up using the step by step set up instructions provided by BT.

I have also contact bt but they say it is nothing to do with them and that it is a username and password issue even though I know these are correct.

I have spent many hours going through this with the people that developed the admin system and that is working fine.
I have driven myself mad checking the e-mail settings and I can't believe there is not a solution to this, having done some research on the web it seems that quite a few people have had problems since BT changed the mail settings.

I hope someone can help as I have work pilling up around me and I'm having to do everything manually :(