How do I check a message I have sent?

What can I check, and can I alter the message?

How to check it!

I want to check a message that I sent in order to see if it has been read [https://eyeemmeff.com/checkmessage?checkuid=XXXXXXXXX].
Yes, you can do that using the "8. Url to check read status." if you have copied the link.
Where do I use the copied link?
You can either just paste it directly into the browser bar, or paste it into the textbox below. If it is a valid link, then the button will be enabled to navigate to the message status.
What should I expect to see?
If the message has not yet been read, and you are within the message expiration period, "1. Select unread message expiration (in hours)" you will see a message saying "Message has not yet been read." See image below:
Check Message Screen Shot Image
What should I expect to see? Continued...
If the message sent time is beyond the expiration period set when the message was created, or the recipient deleted it without reading it, or the unique ID in the URL is not valid, or has been altered, you will see the message: "Message Not Found | Message Expired | Message Deleted". See image below:
Check Message Screen Shot Image 2
And if there is something to see?
If the message has been read by the recipient, the message body/text will have been deleted, but the message details remain until the expiration period is hit. You will see a message saying: "Message Read: dd/MM/yyy HH:mm:ss".
Check Message Screen Shot Image 3

Can I alter the message?

Can edit the message text after I have created the message?
In short, no! Once the message has been generated, it is immutable.
In that case can I delete a message that I have created if I have sender's remorse?
No!(ish), While there is no mechanimm to delete a message from the sender's point of view. If you still have the original link that you sent to the recipient, you can simply go to the message yourself, assuming they have not beaten you to it, and delete it or view it (which will delete it), so that if the recipient tries they will just get the message not found warning.