Outlook.

Thankfully Thunderbird, although most folks here just use the Roundcube web client.

With a giant signature that includes an embedded image.

They are auto-generated and enabled for everyone. Typical corporate bullshit I guess.

Also the image is a 2400px image that has been resized using width and height attributes.

It's a portrait (that thankfully has been downsized and compressed so much, that it's barely recognizable (thank goodness, because it's a horrific photo)), as well as a photo of my physical signature. Oh god do I hate emails and email signatures. And fuck my company for wanting emails to look "authentic" and including this stupid ass signature.