I have created a template in mailjet template using mjml. To use the logo, I have inserted a my logo to image and use the url of this image.
<mj-image src='http://0ojxp.mjt.lu/tplimg/0ojxp/b/lqj1g/0wwo1.png' alt="" width="220px" height="24px"/>
</mj-column>
</mj-section>
But when a send a mail with this url to show the logo, it seems as spam and sometimes the logo not shown. See here how the mail shown

Is there any other way to insert the logo in mjml or am I doing sth wrong when using logo url
You get the email in your inbox, so it's not a spam issue.
This is normal behaviour from Outlook, which is setup so that people have to click to download images. Some people like that - it's a default configuration that can be changed.
Now, the URL is showing up in the inbox in what we call the 'preheader' or 'preview text'. Try adding some text in the alt tag, i.e.
alt="Something", and that should make the URL go away. If not, add a preheader in your html, just after the<body>tag, like so:<div style="display:none;">Some text here</div>and that will make your inbox preview look much nicer.