An Email with a URL written in this way:

<http://www.linuxsmith.com>

Are rendered like this:
<http://www.linuxsmith.com>;

And result in a link like this:
http://[domain].org/SOGo/so/kevin/Mail/&lt;http://www.linuxsmith.com>

Resulting in this error if you try and follow it:

An error occurred during object publishing
the requested object could not be found!