[Mailman-Users] hello, question about mailheaders

hello everybody!.I'm a new mailman user, I'm installing it for a mailing list on my university (UNAM). Until now I haven't had any problems with my configuration, but my boss (teacher) wants me to put a banner on every mail posted on the list. The banner must be a jpeg image and it should be loaded from my server. I thought of putting a <src image> label on my header in regular delivery configuration, but it seems that < is not allowed, the symbol < appears instead; i've tried everything " / and other characters before the < character but nothing seems to work. p.d i put no on my html to text checkbox

If someone answers this , I will be very grateful .

thanks everybody