MessageTag, the program that notifies you when your messages are received and opened is no longer available in a free version.
MSGTAG, which I reviewed (and recommended recently) is now only available in two flavours: MSGTAG PLUS ($20), which works by sending you emails when your mail has been opened, and MSGTAG Status ($60) which runs as a separate dashboard, keeping track of tagged messages and letting you see at a glance whether messages have been received and opened. MSGTG runs on Windows 98, 2000, Me or XP and with any email program which uses the SMTP protocol.
MessageTag plan a version for webmail accounts.
Although 60 bucks is a bit steep for what you get, I still think it’s a great program and I find I still rely on it. If you’re not sure, try out the $20 version (sadly there’s no trial version available).