Well I tried to use same images as in https://bitcointalk.org itself, hoping that it won't go to proxyserver e.g. https://bitcointalk.org/Themes/custom1/images/bbc/email.gif
But I guess it's still going through proxy server even with relative URL e.g. /Themes/custom1/images/bbc/email.gif

By the way this is telegram just an old one https://bitcointalk.org/Themes/custom1/images/bbc/tele.gif. (Again used this because don't not want to upload new images)