1. Copy signature with logo in your Edit signature option of Microsoft outlook from some other mail which has logo or picture in its signature.
2. If this does not work, which probably does not then copy the logo picture from signature in Microsoft one note and right click the pasted logo. You will get Save as option. Save logo on desktop. Then in Edit Signature option of Microsoft Outlook, click on insert picture and insert this picture from desktop location. This will work.
3. If logo size exceeds expectations when point no. 2 as given above applied, then simply copy Signature logo in Microsoft word. Copy it. Go to Edit Signature option of Microsoft Outlook. Paste it here. Same will be pasted. Cut paste it within to match it's position at desired area in the signature.
Out of above 3, the third option generally works even if other 2 options do not.