The contents must be sent using the UTF-8 international charset.
To test it, add “ÔéČuro” in your subject and submit it. If the charset is wrong, you will receive this JSON warning:
{"success":false,"errorMsgs":["The 'subject' value is not correctly encoded. It must be UTF-8 encoded."]}

Depending on whether you have filled in one or both the fields “text” and “html”, the messages will be sent using one of these “Content-Type”:

text text/plain (text only)
html text/html (html only)
text+html multipart/alternative (both text and html)
email client settings will decide which part is displayed

Not required/optional parameters:

fromname sender description
toname recipient description
replyto email address that will receive the replies
returnpath email address that will receive the bounced mails
it must be present among the RealSender’s authorized senders
cc carbon copy email address
ccname carbon copy description
bcc blind carbon copy email address
bccname blind carbon copy description
attach file(s) to be attached - can be present multiple times in the form - 3MB max weight
the file contents must be part of the multipart HTTP POST
enctype=“multipart/form-data” is required for INPUT TYPE=FILE

To, cc and bcc values can contain a single email address or a comma separated list of email addresses.
!! Within RealSender the total number of recipients for each piece of email is limited to 25 (it can be increased up to 100).

The server’s responses are in JSON (JavaScript Object Notation) format:

email sent {"success":true}
email NOT sent {"success":false,"errorMsgs":["..."]}

API Examples