Support » Plugin: MC4WP: Mailchimp for WordPress » Error 503 : Service Unavailable

  • Resolved paresseuxcurieux


    Hi there,

    When I register my Mailchimp API keys it returns Error connecting to Mailchimp: 503 Service Unavailable. I’ve contacted Mailchimp and they cannot help me here.

    There is no reference number available and it seems it is a recurring problem.

    A hand please ?

Viewing 3 replies - 1 through 3 (of 3 total)
  • Plugin Contributor Harish Chouhan



    I can confirm that the 503 error definitely means that the IP your hosting provider is using to connect to the MailChimp API is blocked by Akamai. This is not something we can help with.

    It does not mean that your own private IP is blocked, it may not even mean that your public hosting server IP is blocked, but it does mean that whatever IP your hosting provider uses for outbound cURL connections that are made by Apache/PHP is blocked. This is often an IP address that you share with multiple clients on your hosting server so it’s possible that another client did something to get the IP blocked, completely out of your control.

    There are some sites that show risk scores or spam scores for IP addresses, but I have not found a site that actually can confirm if an IP is on the Akamai blocklist or not, besides your own private IP and that’s not relevant in this case. If you have a way to confirm if an IP is listed in Akamai firewall I would be very much interested in that. Note that this is specifically about the Akamai firewall not about any other blocklist or risk score.

    To see what IP your host was using to connect to MailChimp API you can check your account settings API page, it will show the last 10 successful API calls including their source IP.

    The only possible solutions for this error are:
    – Ask your web host for a new hosting IP address.
    – Migrate to a new web host if your hosting company is unwilling to fulfill your request.
    – Configure your server to connect to the MailChimp API server using a proxy.
    – Wait for the IP to not be blacklisted, this can take a random amount of time and really depends on how/why it got blacklisted in the first place

    Hope that helps. If you have any questions, please let us know!

    Thread Starter paresseuxcurieux


    Seems like it has been solved by itself. Maybe IP adress was unlocked by Mailchimp.

    Plugin Contributor Lap


    Yes, after awhile it can be whitelisted again.

Viewing 3 replies - 1 through 3 (of 3 total)
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