Carnegie Mellon University School of Computer Science

Email Delivery Changes

Greylisting will no longer impact email sent to addresses.


What is happening:

On Wednesday, February 21, 2024, Computing Services will disable greylisting for email sent to @‌ addresses.

Why it matters:

Email greylisting is a method of protecting users from spam by temporarily blocking messages from unknown senders. It requires normal email services to retry the delivery after a short period of time. This is no longer considered to be an effective means of combating spam and results in undesirable email delivery delays. Once greylisting is removed, users with @‌ email addresses can expect email to arrive more quickly.

Have questions?

If you have any questions about this change, please contact the Computing Services Help Center at 412-268-4357 or send mail to