KnowledgeBase Articles » Why am I receiving a "521 5.2.1" error from AOL?

Monday, August 12, 2013, 13:00

Why am I receiving a "521 5.2.1" error from AOL?

Category: General

Solution ID: 00000227

Summary:

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.

Answer:

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.

References: http://www.ietf.org/rfc/rfc1846.txt

Tags: email, error, aol, service, smtp, infrastructure

Link to this article: https://perfectmail.com/kb/receiving_521_aol_error

Updated: Monday, August 12, 2013, 13:00

-- David Rutherford