I am using send_mail() method to send the emails after signup and other custom methods. but problem is that company logo does not appear in the header in any mail.

when i  inspected the src for the image, src had "https://ci3.googleusercontent.com/proxy/yVb1vqgJAboy1esUJ98YgNCHfs4Wp6lyZndeigRCyfeiksfjU4AqG_zWn1RfrRULJ4FuwDzl5guXX1Y=s0-d-e1-ft#http://localhost:8069/logo.png?company=1" for gmail and in hotmail src was inside blockedimagesrc attribute of img tag