cPanel /whm email server configuration

[Quintanilha-RJ]

Good afternoon, I wanted to ask for a technical advice, I currently have 2 cPanel whm servers with all the Email Deliverability configuration done. But I'm having a lot of problem with the servers' Email servers, I currently have a thousand cpanel accounts on this server and I have constant bounce of email falling into blacklists like outlook, gmail etc.
I wanted to know if there is any solution to this problem examples: use several authenticated ips to output email from the server, use an smtp service for all accounts on the server.
I don't know what to do, I just know that I need to solve this urgently, the server is configured for each account to send 300 E-mail per hour I think it's a low value. can anybody help me ?

 

[cPRex]

Hey there! The first thing I would check would be to ensure that your server IP addresses are not on any of the major blacklists, using a tool like Email Blacklist Check - IP Blacklist Check - See if your server is blacklisted. If they are listed there, you'll need to get them removed from those lists before any providers (Outlook, Gmail, etc.) will start allowing your email to go through.

300 emails per hour seems like a large number, depending on the size of the company and website. If there is a mailing list you could certainly hit that limit, but for someone manually typing a message that is 5 emails per minute.

Ultimately, email is tough to maintain, especially with so many accounts. There is just no way to know that one account doesn't have a compromised email password being used to send out spam, until the spam is already sent and you hit those sending limits.