Beatitude allows you to write an email message, destined to be sent to your mailing list in the future.
Your message can be Plain Text, HTML (or both) and can have its contents came from a file on your server or a webpage. It also includes support for attachments.
You may also set the message to be sent on a continuing schedule - say, every day at 9:00am.
Messages can also be dynamic - for example: if you would like to send the above schedule to send a webpage - but only if the webpage has new content.