error: 503 Service Unavailable.

Hi,
Maybe your webhost is blocking access to the MailChimp API servers.
To fix it, you should ask your webhost for the following URL to be whitelisted: https://*.api.mailchimp.com

If that’s not it, it might be that you are blocked in the MailChimp firewall.
Akamai is the firewall MailChimp and many other major websites use to protect their servers, which is why this is somewhat harder to fix.
When this happens, we recommend you to change your IP address because having a bad reputation at Akamai does not just affect the MailChimp API.
There are various ways to go about this.
Ask your webhost for a new IP address.
Migrate to a new webhost if your hosting company is unwilling to fulfill your request.
Configure your server to connect to the MailChimp API server using a proxy.
Advanced
If you have SSH access to your server, running the following command provides a quick way to test if remote requests to the MailChimp server should actually work and what exactly is going on.

curl -v https://us1.api.mailchimp.com/3.0/?apikey=test
Replace us1 with the characters in the end or your API key, after the minus sign.
Replace test with everything in front of the minus sign of your API key.

If you are able to run this SSH command line, or you can ask your hosting provider to do this (don’t forget to replace the us1 and the test part for them before forwarding it to them) so we can make sure what the problem really is. So it would be best to try this first, if possible.

Also see: https://mc4wp.com/kb/solving-connectivity-issues/

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

Hello,

We have same problem. we contacted mailchimp and our IP is not blacklisted. We changed API KEY, unistall et install plug in and always same problem.
Maybe problem on the plug in.

After discution with mailchimp support, minimum version PHP for plug in is 7.35 but, on OVH for sharing server maximum version available is 7.1

Hi I have the same problem for several websites on ovh. some uses Bloom, some Mailchimp for WordPress, even The mailchimp List plugin doesn’t work.
I try everything was describe, no success.
I contact the mailchimp support but for bloom or Mailchimp for WordPress as it is not developp by them they can’t help. I try to find a way for Mailchimp list.
How can we do for the ovh php version ?

I called OVH and they said global version php 5.6, 7.0 et 7.1 include CURL 7.38.

So, this problem don’t come to curl version (for ovh server)

I also use mailmunch plugin, and this one works. It’s an app not an api. If mailmunch work that means that my ip server is not blocked by Mailchimp Akamai ?
I contact ovh by mail, nos answer for now.

Hi,

From the following I would conclude that the IP must be blocked.

Hi I have the same problem for several websites on ovh. some uses Bloom, some Mailchimp for WordPress, even The mailchimp List plugin doesn’t work.

Getting a new IP or asking the provider to route the API requests over another outbound IP can solve this issue. Often hosting providers will offer a private IP for your hosting at additional yearly cost.

I’m not sure on the workings of MailMunch, but I think that plugin will connect to MailMunch instead of MailChimp API?

Hope that helps,

Hello,

Our IP not blocked by akamai mailchimp and no blocked by OVH.

We don’t have solution …

Hello,

In my case, the problem was the Akamai Firewall. we were removed from their black list after 24h. And…blacklisted again few hours later.

My webhost is OVH. And the problem is that i’m on a mutualized server.
if there are a spamer on this mutualized server, i’ll blacklisted all the time…

So @lapzor, you’re right. The solution is probably to pay to have a private IP.

thanks a lot for all your returns, they helped me to better understand the situation.

Sorry to hear that. You are right, if you share the IP with some problematic website it will be a never ending problem.

A private IP, or moving to another shared IP/server if your hosting provider offers you that option. Or move to another hosting provider, some providers put less users on 1 ip, limiting this problem somewhat.

Ovh said that the cURL request of their server are blocked by mailchimp akamai. No clue or solutions on their side, they told me to see with mailchimp..Still wait for mailchimp answer..

Being blocked by Akamai can have all sorts of consequences besides with MailChimp, as other companies also use the Akamai firewall.
You will get unbanned automatically after awhile, by the time MC support replies, but very likely will be blocked again not much later if the reason for the block is not being removed from your shared webhosting server.

1. Ask your hosting provider to move your hosting to another server / ip within their network.
2. Ask your hosting provider for a Private IP so it won’t be blocked if other users on the same server do something wrong.
3. Move to a hosting provider with less users per IP or with stricter policies on what clients they accept to have less change of your shared IP being banned.

Good luck!

We have new solution, we use mailmuch now. with same form in mailmunch.
it’s no better solution but at the moment it’s only solution that we found for our form.
we waiting to unlocked by akamai firewall.

Hey,
Ovh in France have contacted akaimai and for now the restrictions have been removed. Mailchimp for wordpress is conneted.