server responded: Message refused.

server responded: Message refused.

Hi

Why is it that that the zoho server doesn't let me send a perfectly fine email? Works if i use the webmail client, but not using thunderbird on ubuntu 12.04? Is there some kind of filtering going on the zoho outgoing server somehow?

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An error occurred while sending mail. The mail server responded:  Message refused. Please check the message and try again.
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The email payload is simply a URL to someone ?

Thanks