This guide helps you identify and correct errors encountered when using your software or email client(Microsoft Outlook, Mozilla Thunderbird, Apple Mail, etc.).

1. Configuration and essential settings

Unique server name

Enter mail.infomaniak.com exclusively for the incoming (IMAP) and outgoing (SMTP) servers.

Network ports

Configure the recommended incoming and outgoing port numbers.

Email address password

Enter the password for your email address. It is different from the password for your Infomaniak customer account (if necessary, you can add or change the password for your email address). Pay particular attention to the special character $.

SMTP Authentication

Enable authentication in the sending settings of your software. Enter your complete email address as the username and its password.

Valid email address

Make sure that the address used has actually been created in your Manager (or defined as an alias).

Protocol selection

Use the same protocol on all your devices. Do not mix POP3 and IMAP for the same mailbox, as these two protocols do not work well together.

2. Recommended troubleshooting steps

Check the configuration

Compare your current settings with the recommended settings for your software, especially if you have just changed your password.

Try a different network

Try retrieving your emails from a different internet connection (Wi-Fi, 4G/5G hotspot, etc.).

Temporarily disable security applications

Briefly disable your antivirus, firewall, or VPN. If the email service works again, contact the software vendor.

Check your password entry

Enter your password in plain text in a text editor. Depending on your keyboard layout (AZERTY / QWERTY), the A key may correspond to the letter Z and the Q key to the letter A.

Restart the email software

Close and restart your application before attempting another Send / Receive operation. Some software requires a restart to apply the new settings.

Compose a new test message

Do not reuse an existing draft. A message saved in the Drafts folder before you modified your settings may retain the old, problematic configuration.

3. Troubleshooting common errors

Errors of the type 0x800... (Outlook)

Refer to the guide to resolving 0x800 errors.

Certificate error (SSL / TLS)

Consult the dedicated guide on certificate errors.

550 5.7.1 relaying denied or Proper authentication required errors

Read the guide on relay and authentication errors.

535 5.7.0 authentication failed error

Please refer to the guide on authentication failure.

Timeouts and Port 25 Blocking

Observed messages: "573 Antispam: Authenticated connection not possible. Please use port 587 instead of port 25.", "An operation on the server timed out" or "the timeout period has expired" (errors 421, 573, etc.).

Solution: Never specify port 25 as the SMTP port, as most Internet Service Providers (ISPs) block it. To send emails without being blocked, use the recommended ports (such as port 587 or 465).