This information applies only to those who received an error message similar to the following when trying to send email to a UB (@buffalo.edu) email address:
Remote host said: 554 5.7.1 Service unavailable(4);
Internet Service Providers (ISPs) (e.g., Roadrunner, Yahoo, etc.) provide the email servers their customers (you) use to send email. These email servers are shared by many people.
UB uses third-party "reputation services" to determine whether an ISP's email server is sending spam. If one or more individuals on an email server sends spam, the reputation service will report that the server is sending spam.
If you have received an error message similar to the one above, it means that reputation services have reported to UB that your ISP's email server has been sending spam. Based on that report, UB has temporarily blocked your ISP's email server from sending mail to UB.
Please inform the email administrator at your ISP (e.g., Roadrunner, Yahoo, etc.) of the issue so that they can work to fix the spam problem and get their mail server unblocked. Be sure to send your email administrator the error message you received and any errors contained in any email message that was returned to you when you tried to send to UB.
Try again later to send your email to UB. Email servers are usually only blocked temporarily.