SMTP Authentication Fails with App Password – “535 Authentication Failed” Error

SMTP Authentication Fails with App Password – “535 Authentication Failed” Error

Hello,

I'm trying to send transactional emails from my WordPress website using the WP Mail SMTP plugin with Zoho Mail (smtp.zoho.com on port 465 with SSL).

I've created and used a Zoho Mail app-specific password for SMTP, and verified that:

  • The email and password are correct

  • SMTP is enabled on my account

  • I'm connecting via ssl://smtp.zoho.com:465

  • I tried forcing the authentication method to LOGIN (as per PHPMailer recommendations)

  • I’ve tested from multiple accounts using the same domain

Despite all of this, I keep getting this error in the logs:

SMTP INBOUND: "535 Authentication Failed" SMTP ERROR: Password command failed: 535 Authentication Failed SMTP Error: Could not authenticate.

Can you please help me:

  • Confirm that SMTP access is properly enabled for my domain/account

  • Verify if there’s any server-side issue with authentication or blocked connection

  • Ensure that my Zoho Mail account allows external SMTP clients (like WP Mail SMTP) to authenticate and send emails

Thank you!

    • Sticky Posts

    • Pocket from Mozilla is closing shop. Don’t lose your favorites . Move them to Zoho Mail Bookmarks now! 📥🔖

      The end of Pocket shouldn't mean the end of your important links and content. Easily import them into Zoho Mail's Bookmarks and continue right where you left off. You can bring over your entire Saves, Collections, and tags just the way they are. Bookmarks
    • Zoho Mail POP & IMAP Server Details

      Hello all! We have been receiving a number of requests regarding the errors while configuring or using Zoho Mail account in POP/ IMAP clients. The server details vary based on your account type and the Datacenter in which your account is setup. Ensure
    • Workplace - Zoholics Europe Customer Awards

      Dear Zoho Mail Community! 📣 We're excited to announce that at this year's Zoholics events across Europe, we're holding customer awards for the first time ever! Workplace - Zoholics Europe Customer Awards This is your chance to shout about the amazing
    • Important update on Group Management | Zoho Mail

      Dear Zoho Mail Community, This post is to inform you all of the following updates on the Group Management in Zoho Mail. Group Member Addition: If a group member is added to an organization group in a Zoho Application, the member will be automatically
    • Mastering email etiquette and best practices to follow in Zoho Mail

      Hello Zoho Mail Community, We’re thrilled to invite you all to our upcoming webinar: Mastering email etiquette and best practices to follow in Zoho Mail. Join our live webinar for expert etiquette tips to enhance your professionalism and elevate your

    Nederlandse Hulpbronnen