Best practice for requesting many certificates

I’ m looking for advise on requesting many certificates via the Plesk Let’s Encrypt plugin. The case is a WordPress multisite environment running on a VPS with Plesk. It contains around 6500 subsites, each with their individual domain names which are aliases for the main domainname of the WP multisite. Thanks to the Plesk Let’s Encrypt update we can now request SSL certificates for domain aliases as well. I want to start requesting certs as soon as possible, but I’m looking for the best approach.

The Let’s Encrypt plugin works great, however I’m wondering what is best practice as in the number of certificates that can be requested/renewed per day? I can imagine that requesting 6500 SSL certificates at once is not a good idea for both my VPS and the Let’s Encrypt API. Does anyone have experience with the Plesk Let’s Encrypt plugin and can advise on the max number of certs to request per day to prevent issues later on?

I found this article about rate limits, and it explains pretty well how many certificates I should request per week per domain. Does this rate limit also count for domain aliases? I mean in the sense that you can request a maximum of x aliases per domain?

I don’t think that domain aliases should pose any additional problems for you. They are just ordinary additional names that go on a certificate, of which you can have 100.

The only way I’ve seen them be problematic in the past is when all of the accounts on the server used a shared common eTLD+1.

For example:

Account A:

Account B:

The use of can be problematic when it comes to rate limits. However this isn’t a terribly common pattern to begin with.

Thanks for your advise @_az . I won’t run into the scenario from your example because of the unique domains of the subsites. Thanks for you help and clarification!

By the way, you might also want to look at

You can see that the guide hasn’t been updated in a while. If you have any experiences or questions that it would be useful for us to address there, please let us know!

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