How can I manage graphic scaling in email signature using Mail App?

I added my logo in Gmail signature like so: it renders perfectly crystal clear, before sent, and after arrived on the other end. I send it to myself and opened it on my MacBook, it looks perfect as is. See below: Then I copied that ***exact*** signature to **Mail > Preferences**, save it, quit **Mail** App, and tried to send it out. It blows up so huge... How do I **solve** this issue? does anyone else face this issue ? ____ I've tried to resize that logo to 100 x 50 px, but it makes my image very **pixelated**. Any suggestions would be greatly appreciated.