There are whole industries that have formed to combat this with limited success. You can look at a few of the more prominent Email Service Providers like
Constant Contact and
Campaign Monitor and their sites are filled with tips, tricks, and workarounds for the hundreds of different ISPs and mail clients. However, ultimately they conclude its up to the end user to add the sender to their safe list. Fellowship Technologies is doing everything within our power to be compliant with the ISP expectations (which are far and above the requirements of CAN-SPAM). Unfortunately, there is still no centralized committee, agreement, or standard to which all ISPs and email clients subscribe to make this a smooth process for anyone. I recently added picture wrapped by a URL to my work email signature. I use MS Outlook as my outbound email client and now my work emails are ending up in the SPAM/JUNK folders of friends, family, and clients. As
Benjamin Zander would say... How unnecessary!!