What does SMTP error 550 5.5.5 mean and how do I fix it?

Email marketer from SendPulse suggests checking the recipient's email address for typos and ensuring the sender's IP address isn't blacklisted. They also recommend contacting the recipient through another channel to confirm their email settings and request whitelisting.

Email marketer from Mailjet shares that a 550 error is a permanent rejection of the email. It often means the email address doesn't exist or the recipient's server is blocking the sender. The error `550 5.5.5` specifically indicates issues with policy restrictions.

Email marketer from StackOverflow user 'MailGuru' explains that 550 errors are generic permanent failures. He indicates that the extended code '5.5.5' usually implies a specific policy reason for the rejection, such as sender restrictions or content filters, and recommends analyzing server logs for details.

Email marketer from MailerCheck says that a 550 error suggests a permanent deliverability issue. They recommend checking your email list hygiene and removing invalid email addresses, as sending to these addresses can damage your sender reputation and cause further rejections.

Email marketer from Email Marketing Forum user 'EmailPro' shares that he's seen '550 5.5.5' errors occur when the sending domain doesn't have proper SPF or DKIM records set up. He recommends ensuring that authentication is correctly configured to improve deliverability.

Email marketer from ActiveCampaign says that if you receive a 550 error, the problem typically lies with the recipient's server configuration or the recipient's email address itself. Recommend verifying the address and contacting the recipient's IT support if you continue to get the error.

Email marketer from Litmus highlights that a 550 error is a hard bounce, meaning the email will not be delivered. The '5.5.5' code means it's not a technical issue like a full inbox, but something with the recipient's server configuration rejecting the email.

Email marketer from Reddit user u/EmailHelp suggests that the error could indicate the recipient's server has identified the sender as a source of spam. He recommends checking sender reputation using online tools and contacting the recipient directly to ask them to whitelist the sender.

Email marketer from GlockApps suggests checking your sender reputation using their tools. A 550 error could mean your IP is on a blocklist or your domain reputation is poor, causing the recipient's server to reject the email. They also advise warming up your IP and reviewing your sending practices.

Expert from Email Geeks shares that the fix is on the recipient's end and the sender cannot fix it from the outside. They should tell the recipient IT to resolve the issue.

Expert from Email Geeks shares that in this kind of scenario, it's common for the client or client IT to say "oh, we've whitelisted it, you should be fine now!" The bounces you are seeing show that the whitelisting is not working or not implemented properly.

Expert from Spam Resource shares that 5xx errors are hard bounces which means permanent failures which are non-deliverable. The 550 code means the remote server recognized the email, but refused to accept it. They also advise cleaning your lists to prevent these happening again

Expert from Email Geeks explains that the email address likely only accepts mail from pre-approved senders and to resolve it, the recipient needs to configure their email to allow mail. If the rejection happens before DATA, then the sender address that needs to be on the allow list is the Envelope From.

Expert from Word to the Wise explains that a 5.X.X error indicates a permanent error, usually caused by something the sender cannot fix. The 550 code often signals a general rejection by the recipient's server due to policy or spam filtering rules.

Documentation from Microsoft Support explains that error 550 5.5.5 indicates a policy rejection. This means the recipient's mail server has policies in place that prevent the message from being delivered, often related to spam filtering or sender reputation.

Documentation from Exim Wiki indicates a 550 error generally means a permanent failure on the receiving server. The specific code 5.5.5 can be tailored by the admin of the remote server, but the general meaning implies that the remote server operator is making a deliberate choice to not deliver your mail.

Documentation from Cisco explains that 5xx errors are permanent failures. Specifically, 550 indicates that the requested command failed because the user's mailbox was unavailable (e.g., mailbox not found, no access, or command rejected for policy reasons).

Documentation from Postfix explains that the 550 code corresponds to a permanent failure which is used by the receiving server. The '5.5.x' is a receiving side error and means that there is a syntax or protocol error. The main fix is not on the sending side but the receiving.

Documentation from RFC 3463 specifies that 5.5.x status codes generally relate to protocol or syntax errors, meaning the command couldn't be performed due to issues like invalid arguments or unimplemented features. In context, 5.5.5 often points to a policy violation.