SMTP errors and email delivery errors

Errors, their explanation and solutions

  • Invalid Email Address Error Codes

    Last Updated: 22.01.2020

    If you send bulk emails, you may face the problem of delivery errors. Knowing the reasons will help you cope with it and increase conversions. After registering with SendPulse, you're welcome to monitor your campaign statistics, including the errors. Keep on reading this article to discover the causes and ways to avoid errors.

  • The 550 5.1.1 Error

    Last Updated: 20.01.2020

    There are several possible reasons that you received this error. In this guide, we'll talk about the reasons and help you resolve this nasty error.

  • Spam Related Delivery Errors

    Last Updated: 21.01.2020

    SMTP Error 450 4.7.1

  • Error 503

    Last Updated: 27.01.2020

    Have you ever faced Error 503 – Valid RCPT command must precede DATA while sending emails?

  • SMTP Error Codes

    Last Updated: 25.02.2023

    SMTP is responsible for delivering your email campaigns. If you send bulk emails, you have probably faced the problem of various SMTP errors that prevented your subscribers from receiving your emails. Mind that not every reply means an error. It can be a response to a command, including important information about a server. To understand what's wrong, you should know what the codes mean.

  • The 554 5.7.1 SMTP Error

    Last Updated: 30.01.2020

    When sending an email, you should take into account two mailing servers: yours and the recipients.

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