I am getting this error using an email aggregator.   The application is called Iqtell (www.iqtell.com) and I use it because it allows me to see all my different mail accounts in one place.  However, for my hotmail account I cannot send email.  It keeps giving me this error message.  All my other accounts work fine: yahoo, aol, exchange, gmail, and apple.  Its only hotmail that doesn't work.

"535 5.2.1 Login to your account via a web browser to verify your account."

I have tried to login as suggested by the error message and see if that verifies me but it doesn't.  Are you expecting me to login to the hotmail.com web page on the email aggregator servers?   That is impossible since I don't have access to them or own them.  They are a third party application.   I also contacted iqtell support and they said the servers are linux terminal servers with no gui.  So its impossible to reach the hotmail webpage from their servers.

Should I switch to using Gmail?  I have no problem with gmail and it supports IMAP.