[otrs] image in OTRS signature

Hello, i would like to ask you, if you can verify for me that OTRS 2.4.7 is supporting images in signatures. Probably I must somehow force OTRS to use html emails instead of plaintext because of <img src="http://site.com/image.jpg" /> tag. I need to add our company logo as a signature at the end of "reply to customer" emails. Thanks for help, regards, Martin