Monday, August 12, 2013, 13:00
Solution ID: 00000227
Why am I receiving one of the following error messages: 521 5.2.1 : AOL will not accept delivery of this message; 521 5.2.1 : Service unavailable. Please try again later.
The SMTP reply code 521 indicates an Internet mail host DOES NOT ACCEPT incoming mail. If you are receiving this error it indicates a configuration error on the part of the recipient organization, i.e. inbound e-mail traffic is being routed through a mail server which has been explicitly configured (intentionally or not) to NOT ACCEPT incoming e-mail.
To resolve this issue the recipient organization needs to resolve their infrastructure issues.
In large organizations, with many mail servers, this issue may be a transient error isolated to a particular mail host or cluster configuration (e.g. in a mail server failover situation.) If you are unable to contact the organization to have them resolve your issue, waiting a short time and resending may be all you need to do.
Tags: email, error, aol, service, smtp, infrastructure
Link to this article: http://www.perfectmail.com/kb/receiving_521_aol_error
Updated: Monday, August 12, 2013, 13:00
-- David Rutherford