Has any one found a solution to Outlook.com with the extra margin and line-height. I’ve tried different codes to override it and have not found any solution to outlook.
I've tried to add margin in the <p> tag and outlook just strips it out, also adding this above my header:

.ExternalClass{
    width:100%;
}

.ExternalClass,
.ExternalClass p,
.ExternalClass span,
.ExternalClass font,
.ExternalClass td,
.ExternalClass div{
    line-height: 100%;
}

and nothing. Does anyone know a better solution please.