I've been Googling to find this issue for a month now, on and off, and haven't been able to find a solution yet. I've determined the CAUSE of the solution, but not the fix. Our company HTML signatures are expensive and look pretty sweet on 90% of computers in the company. Like so: Unfortunately, it seems with anyone who uses a standalone Surface (We've got Surface Pro 2s and 3s, I believe), they've changed the display size to be able to read anything on their screen. That means, however, that their personal signature on outgoing emails -- and anyone else's signature on email threads they reply to -- gets blown up to painfully overblown sizes. Below is an example of my signature having been blown up by his replying to one of my emails. His show up the same size. Can make the image a bit smaller as you move the display slider, as I'll mention below, and it gets normal when the slider's all the way to 'Small'. The owner, our main sales people, all use SP2/SP3 and have this issue, and it doesn't look good on us. I was able to play around with our Sales guy's SP3 when he was here and found that the Display Size slider fixed the issue. But that made everything on his screen completely small and illegible. There's a workaround for this, right? Any help would be greatly appreciated. We're running Microsoft 365 / Outlook 2013 for our mail server, Windows 8 on all.