Hey there! I took a look at your recent test sends. None of them bounced and we received word back from your mail server that all tests were successfully received. Since it didn't reach your inbox or spam folder, there's a good chance your mail server is holding on to the message.
I sent myself a test and received it in my inbox right away; it's likely that this issue is only for addresses with the same domain as your sender address (@law.sc.edu). You can resolve this by having your IT department whitelist:
None of my test emails are going through on the first try either! We are having process delays at my office due to this hold-up. The test email function has been very "hit or miss" for the past several days. Will you please take a look at our account, as well?