How to resolve and prevent 554 5.7.1 : Relay access denied email errors in Linux and Windows mail servers
Emails play a crucial role in online communication. Business orders to meeting invites, lost or delayed mails can end up creating disgruntled customers.
In our role as Website Support Specialists for online businesses, we resolve hundreds of mail issues every day. A commonly encountered email bounce error faced by web hosts, website owners and server owners is:
554 5.7.1 <email@example.com>: Relay access denied
‘554 5.7.1 : Relay access denied’ error means that either the sender has failed security checks or the recipient’s mail server is misconfigured, and today, we’ll take a look at:
- What causes Relay Access Denied error
- How we fix it for server owners (eg. web hosting provider)
- How we fix it for mail users
- How we prevent this error in our customer’s (eg. web hosts) servers.
What causes Relay Access Denied Error?
When a mail is sent, it first goes to the sender’s mail server (aka MX). Then it’s RELAYED to the recipient’s MX, and from there to the recipient.
Here, TWO servers are involved – Sender’s MX and Recipient’s MX. If either one of these servers reject the mail, a Relay Access Denied error is shown to the sender.
Case 1 – Sender’s MX rejects the mail
Every mail server requires its users to provide a username and password to send mails. This is to keep spammers out. But very often valid mail users forget to turn on authentication in their mail clients, and the MX rejects their mail.
Bobcares manages the website support of several businesses. A quick look at the support tickets we handle shows that 95% of ‘Relay Access Denied’ errors are caused by incorrect SMTP settings.
So, when customers come to us facing this error, the first thing we check is their mail client settings. By guiding users with the correct settings specific to each mail client and mail server, we help them send emails without this error.
Case 2 – Recipient’s MX rejects the mail
The recipient’s mail server will accept a mail only if it can verify that the recipient is a valid user in that server. For eg. if the recipient’s account is cancelled or inactive, it won’t accept the mail.
Our Support Specialists have often traced the origin of these errors to:
- Improper sender MX configuration (eg. SMTP auth settings disabled)
- Inactive or cancelled recipient mail address
- Recipient’s DNS MX records pointing to the wrong server (often after a migration)
- Recipient’s user database errors
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We’ve seen two variations of this error in web hosting servers:
- 554 5.7.1 Relay Access Denied – The recipient’s mail server logs show this error when a mail is rejected.
- 454 4.7.1 Relay Access Denied – This error is seen in server logs when the recipient server is temporarily unable to accept mails. The mail delivery will be attempted again later.
So, if a website owner has started seeing these errors after a recent config change, or migration, or new server setup, we check the MX configuration of the domain and resolve any errors in that.
Pro Tip : If mails to several mail servers are bouncing, the mail server’s configuration could be incorrect. If mails to only a couple of recipient addresses are bouncing, the issue might be specific to those accounts.