Your message will not be accepted unless you have gone through the join process. ... Can I send a message in HTML?

As I've noted, some recipients won't accept HTML-formatted e-mail or other mail with non-text attachments, because it triggers filters designed to keep out spam or viruses. Among those who bounce non-text messages are some companies' technical support and customer service departments, who will send back messages with attachments and tell you to resend them as plain text. One amusing example of such is Bonzi, which has a free download that supposedly "enhances" your PC experience (I don't recommend you install it; it's reputed to be annoying adware, and maybe "spyware" too; once it gets into your system, it won't go away, and might also be sending personal info of yours to its manufacturer). Anyway, their automated response they send to anybody who e-mails them in non-text form (which I found out because apparently some virus e-mailed itself to them forging my address as the "From" line, triggering this response to me even though I had never e-mailed them in my life), includes this passage: