Outlook 2011 has been working since install. Two days ago anytime I try to send an email I get an authentication rejected error. 5.7.0. I've re-entered the password, deleted and re-created the account information, verified port settings and other settings; turned off the firewall and rebuild the identity. All of which is the same result. Also contacted the ISP which hosts the email and they say it's an Outlook problem.

There are two accounts setup. One works for incoming and outgoing and the other which is the default account is the one that has the problem.

Any help would be greatly appreciated!