❗ What Does the 'Server Authentication Failed' Error Mean?

In this article, we’ll explain the ‘Server authentication failed’ error message, which may appear when Mailbird is unable to authenticate one or more of your email accounts.

This issue typically occurs when your email server loses authentication access to your inbox. The good news? It’s normally very easy to fix, and we’ll guide you through the process step by step.

🛠️ How to Resolve the Authentication Error

The first step is to remove and re-add your email account in Mailbird.

If you’re using an IMAP connection, your emails will be downloaded again automatically once you re-add the account, so no data will be lost.

However, if you’re using a POP3 connection, it’s important to contact our Support Team first. Removing a POP3 account without creating a backup will result in permanent loss of email data, so we'd prefer to guide you through the process.

🧹 Steps to Remove Your Email Account

1. Click the Mailbird Menu in the top-left corner (☰, i.e. the three horizontal lines)

2. Select Settings

3. Click on Accounts

4. Choose the account you want to remove

5. Click Remove on the right-hand side

🔍 Checking Whether You Use IMAP or POP3

Follow these steps to check your email protocol:

1. Go to the Mailbird Menu in the top-left corner (☰ three horizontal lines)

2. Click on Settings

3. Select Accounts

4. Double-click the account you’re checking

5. Look at the port number:

   • If it’s 995 or 110, it’s a POP3 account

   • Any other number means it’s an IMAP account

✅ After Re-Adding Your Account

Once you’ve re-added your email address, the error should usually be resolved.

Still having trouble? No worries. Just contact our Customer Happiness Team, and we’ll always be delighted to help.