I’ve been getting a lot of bounced emails lately due to a client doing mass mailing with most of the recipient emails either does not exist or server is unreachable and it’s clogging the server’s mail queue. The server is using WHM/Cpanel that manages all the tweaks and settings of the server.
Below is a guide on how to put a limit on the number of outgoing emails allowed to be sent from the server per user, per hour.
Login to your WHM account, under Server Configuration, look for Tweak Settings then look for “Max hourly emails per domain” section and enter the number of outgoing emails you want to process per hour for every domain.
Once you have the number of emails to process per hour set, go to “Mail” tab and look for the “The percentage of email messages (above the account’s hourly maximum) to queue and retry for delivery” and set it to how many percent of those that exceeds the number of emails to process per hour be placed on queue for delivery the next hour.
Save your changes and restart your mail services.
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