If you are using myUMBC Gmail, users 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 server. Emails to students and instructors were actually sent using eXplorance Blue email servers. This is normal and is a security precaution that UMBC Gmail takes when third-party services are used to send university email.
The message says "UMBC Mail couldn't verify that umbc.edu actually sent this message (and not a spammer). This is normal. The links in the email are safe to click.