If you are using myUMBC Gmail, you will see a 'question mark' next to the sender name. UMBC Gmail does this when it recognizes that an email was not sent from its UMBC Gmail servers. Emails to students and instructors were actually sent using eXplorance Blue email servers. This is an informational notice provided by Gmail and should not be a cause for concern.
When you hover your mouse over the question mark, a pop-up appears with a message reading, "UMBC Mail couldn't verify that umbc.edu actually sent this message (and not a spammer)." This is normal. Be assured that the links in the email are safe to click.