I agree with the answer from the previous post:https://community.marketo.com/MarketoDiscussionDetail?id=90650000000Pr1oAACIt's not a good idea and you can't do it via Marketo's ema...
Also, make sure you add the class "mktNoTrack" so that it doesn't popup a re-direct window. You probably just want it to bring up the compose email window. The only side effect is ...
It's actually just an issue with excel. You can fix it in two seconds:
Select the entire column.
Go to Data > Text to Columns.
Choose "Fixed width."
Remove all break lines....
You don't even need that, this can be done from Excel itself. Just right-click the cells and choose "Format Cells," then pick the formatting you'd like.