Merged emails in office 2003 are not reaching their recipients

Something I did worked. I tested and sent mail merges all day yesterday. All
test emails arrived in my test inboxes.

I shut down my computer. I had a nice night's sleep. I booted up my
computer. I tested emails, hoping my troubles were a thing of the past.

The test emails did not arrive today.

This is surely what happened when they worked before (the mysterious day
where the emails were delivered then stopped arriving the very next day)

With this information, is my problem any easier to solve?

Thank you!

Amy