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If you received a DSN (Delivery Status Notification) email notice attempting to deliver email to @canisius.edu that contained the SMTP (Simple Mail Transfer Protocol) status code 451 4.7.1 with the text "Connection not allowed due to bad reputation" followed by a link to this page, you will need to follow the steps provided below.

  • Follow the procedure at https://ipcheck.proofpoint.com/ to lookup your email server IP and request removal from the list
  • If you have not received a response using the prior step, and you are conducting business with the college, you will need to contact the ITS Help Desk
    • normal business hours are (all times are NY time):
      • Monday - Thursday 8:00am - 5:00pm
      • Friday 8:00am - 4:30pm
    • phone: 716-888-8340
    • email: helpdesk@canisius.edu  (you will need to use an email account not hosted by the server that is blocked)
  • You can also contact the person at Canisius with whom you are dealing and have them contact the ITS Help Desk on your behalf
  • Note that none of the above guarantees we will accept email from your server


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