Sending email is fairly simple using the acs-mail-lite package. Sending HTML email is only slightly more complicated.

    set subject "my subject"

    set message "<b>Bold</b> not bold"

    set from_addr "me@myemail.com"

    set to_addr "me@myemail.com"

    # the from to html closes any open tags.
    set message_html [ad_html_text_convert -from html -to html $message]

    # some mailers chop off the last few characters.
    append message_html "   "
    set message_text [ad_html_text_convert -from html -to text $message]
        
    set message_data [ad_build_mime_message $message_text $message_html]
    
    set extra_headers [ns_set new]

    ns_set put $extra_headers MIME-Version [ns_set get $message_data MIME-Version]
    ns_set put $extra_headers Content-ID [ns_set get $message_data Content-ID]
    ns_set put $extra_headers Content-Type [ns_set get $message_data Content-Type]
    set message [ns_set get $message_data body]
    
    acs_mail_lite::send \
        -to_addr $to_addr \
        -from_addr $from_addr \
        -subject $subject \
        -body $message \
        -extraheaders $extra_headers