Here is howto:
1. Open Total Commander
2. Browse to the "Windows" folder
3. Find the file: thread_sms.htm
4. Press to edit with the little notebook below from Total Commander

You will see this HTML code:
Code:
<html XMLNS:Inbox>

<head>
<object id="HTMLFormFactory" CLASSID="clsid:29d48cf7-ed6a-4a9d-a17a-ae9115c07a90" />
<?IMPORT NAMESPACE="Inbox" IMPLEMENTATION="#HTMLFormFactory" />
<link rel="stylesheet" href="file://\windows\thread_style.css" type="text/css" />
</head>

<body>
<Inbox:ThreadIFrame>
<Inbox:content id="THREADIFRAME" links />
</Inbox:ThreadIFrame>

<div id="threadbottom">
<hr class="divider" size="1" />
<Inbox:ComposeBodyCount>
<Inbox:content ID="COMPOSEBODYCOUNT" format="%1!d!/%2!d!%4 (%3!d! messages)" title />
</Inbox:ComposeBodyCount>
<Inbox:ComposeSubject class="sms">
<Inbox:content id="COMPOSESUBJECT" width="98%" height=35 spell focus count links noclearonbackpresshold limit=0 autocap inserttab scroll />
</Inbox:ComposeSubject>
</div>

</body>

</html>
go and find:
<Inbox:content id="COMPOSESUBJECT" width="98%" height=35 spell focus count links noclearonbackpresshold limit=0 autocap inserttab scroll />

Replace the height "35" with "90"

Like so:
height=35 to height=90

*You can put the value as much as you want really....just see 35 as 2 text lines*

Hit save and softreset. And There you go. Space....... :P
If I have helped you, support Parkinson's

“When I was 5 years old, my mother always told me that happiness was the key to life. When I went to school, they asked me what I wanted to be when I grew up. I wrote down 'happy'. They told me I didn't understand the assignment, and I told them they didn't understand life.” ~ John Lennon