Ok thanks for the explanation. There's no indication that sendinblue will be any different from mailchimp. They could pull the plug just as easily.
As for the servers and applications that's fine if you just need a virtual server with some apps. I know vultr has bare metal and maybe some of the others do too. But if you aren't on bare metal and get hit with DDOS like FR does, they will pull you off their virtual server in a heartbeat to protect their other customers.
DDOS:
1.) Cloudways provides DDoS prevention at its networking core.
2.) Keep updated:
WordPress installation
WordPress themes
WordPress plugins
PHP version on the server
Apache version
MySQL version
OS version
Any other script or software that you use
3.) Install a security plugin such as WordFence
4.) Add the following code into your .htaccess file:
# START XML RPC BLOCKING
<Files xmlrpc.php>
Order Deny,Allow
Deny from all
</Files>
# FINISH XML RPC BLOCKING
I'm beginning to think I should have included my Cloudways affiliate link.