Error: SMTP Error 542

What's Causing This Error

SMTP error 542 occurs when the recipient mail server rejects the email. This error code means a bad connection to the recipient's email server. However, this specific error code has many hidden reasons for the email message to fail.

Some of the most typical issues are:

1. IP address/email domain blocked
2. Security controls blocking emails
3. IP address blocklisted

Solution - Here's How To Resolve It

Troubleshooting this error is tricky since the error code can hide various underlying issues with the email communication and system. Therefore moving down from the most common problems can help narrow the issue swiftly.

1. IP address/email domain blocked - Check if the email server is actively blocking the IP address.
2. Security controls blocking emails - Check if any security controls on the recipient's email server are actively blocking the emails.
3. IP address blocklisted - Check if the IP address or email domain is within a blocklist.