The '550 5.4.1 Recipient address rejected: Access denied AS(xxxx)' error signifies a permanent email delivery failure stemming from the recipient's server. This rejection is usually due to security policies, anti-spam measures, sender reputation issues, or problems with the recipient's address. The 'AS' code often indicates a tenant-level anti-spam block. Common causes include incorrect recipient address, the sender being blacklisted, or misconfigured authentication records (SPF, DKIM, DMARC, and PTR). Resolution involves verifying the recipient's address, ensuring proper sender authentication, checking for blacklisting, reviewing email content for spam triggers, and investigating recipient-side configurations.
9 marketer opinions
The '550 5.4.1 Recipient address rejected: Access denied AS(xxxx)' error indicates a permanent email delivery failure. This typically means the recipient's server has blocked the email due to security policies, spam filters, or sender reputation issues. Possible causes include an invalid recipient address, the sender's IP or domain being blacklisted, or misconfigured authentication records (SPF, DKIM, DMARC, and PTR). Resolution involves verifying the recipient address, ensuring proper sender authentication, checking for blacklisting, and reviewing email content for spam triggers.
Marketer view
Email marketer from MXToolbox notes that a 550 error is a permanent rejection. They suggest using MXToolbox's tools to check if the sender's domain or IP is blacklisted and to verify proper DNS records.
17 Jul 2023 - MXToolbox
Marketer view
Email marketer from Sendinblue answers that a 5.4.1 error usually means the destination address rejected the message. The sender may need to contact the recipient by another means to resolve the issue or to confirm the email address.
2 Sep 2024 - Sendinblue
2 expert opinions
The '550 5.4.1 Recipient address rejected: Access denied,' particularly with the 'AS' code, is a permanent failure indicating a policy rejection by the recipient's mail server, likely due to tenant-level anti-spam measures rather than a simple 'no such user' error.
Expert view
Expert from Email Geeks explains that the "550 5.4.1 Recipient address rejected: Access denied" error, especially with the 'AS' code, often indicates a block implemented by the tenant's anti-spam measures, rather than a simple 'no such user' error.
10 Jul 2023 - Email Geeks
Expert view
Expert from Word to the Wise explains that 5xx errors are permanent failures. A 5.4.1 code generally indicates a policy rejection and means the mail server will not send the message. In cases with the AS code, this is more likely to be an anti-spam policy block.
28 Nov 2022 - Word to the Wise
5 technical articles
The '550 5.4.1 Recipient address rejected: Access denied' error indicates a permanent rejection of the email by the recipient's server, often due to security policies, filtering, or issues with the recipient address itself. Potential causes include incorrect recipient address, sender being blocked, SPF record issues, or general email configuration problems. Resolution involves verifying the recipient address, checking sender reputation, ensuring proper email authentication (SPF), and investigating server configurations.
Technical article
Documentation from RFC 3463, which defines enhanced mail system status codes, explains that a 5.4.1 status code generally signifies a problem with the destination email address. The sending system may need to verify the validity of the recipient address.
16 Sep 2024 - RFC Editor
Technical article
Documentation from Microsoft Support explains that the '550 5.4.1 Recipient address rejected: Access denied' error indicates that the recipient's email server has rejected the message due to security policies or filtering. It suggests checking the sender's IP address and domain reputation to ensure they are not blacklisted.
17 Oct 2022 - Microsoft Support
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