The following problems may arise from sending image-only emails:

• Mail filters will usually block an image-only email as they are a prime tool of bulk spammers
• If the email is not automatically bounced, the spam filter will often dump it straight into the junk or spam folder
• Image-only emails can generate spam complaints, high bounce rates and low open rates
• If a recipient’s mail client does not allow images, they will receive a blank email. If a recipient sets their client to receive text-only emails, they will receive no email at all.

If you must use an image, make sure it is no wider than 600 pixels and takes up less than 350 KB. We also recommend that you include a text version of your email.