If an email address appears to work outside of Luminate Online, the best suggestion is to change that Constituent's Email Status back to Good, then after the next email message sent that should be received by that Constituent, do one or both of the following:

Check the Hard Bounce Report for that message.
  1. Go to Email -> Email Campaigns.
  2. Click the Campaigns tab.
  3. Click Manage next to the Email Campaign.
  4. Click the Reports tab.
  5. From the drop-down choose Hard Bounce Report.
  6. Click Go.
  7. Choose the email message or messages that were last sent to the Constituent.
Check the Emails Sent under Interactions.
  1. Go to the Constituent Record.
  2. Click the Interactions tab.
  3. Click Emails sent.
  4. If the message is listed their, it means it was successfully sent without receiving a Hard or Soft Bounce.