Email volume, performance and account size limits?

[smatt]

Hi all,

Looking for some guidance please;

We have a WHM VPS we have finished migrating our accounts to - 49 in total. Everything is running nice and smooth and the migration process was largely straight forward (kudos to the Transfer Tool).

Currently the server is processing ~1000 a day received and the same again sent.

We have a new client who wants to move their 600 email accounts to us. Is this a problem for a single cPanel account having so many?

If we put them on their own IP we don't compromise the reputation of the server but will performance for the other accounts be effected? Overall server performance is very good, more thinking of Exim's queues and SpamAssassin working overtime.

Lastly, are there any cPanel plugins / options for an improved interface for managing high volume of email accounts?

Any input is welcome. Thanks.

 

[24x7server]

Hello ,

I will suggest you setup their own IP for the mail so that you will not face any issues with the mail.

And for the mail manage you can use : ConfigServer Mail Manage (cmm) plugin on your server.

 

[cPanelMichael]

We have a new client who wants to move their 600 email accounts to us. Is this a problem for a single cPanel account having so many?

If we put them on their own IP we don't compromise the reputation of the server but will performance for the other accounts be effected? Overall server performance is very good, more thinking of Exim's queues and SpamAssassin working overtime.

Lastly, are there any cPanel plugins / options for an improved interface for managing high volume of email accounts?

Hello,

It depends on the volume of email utilized by the additional email accounts. While assigning that domain name it's own IP address and configuring it send emails from that IP can help, your server could still get flagged for SPAM based on the hostname or through other methods. This document is useful to help avoid that:

How to Keep your Email out of the Spam Folder - cPanel Knowledge Base - cPanel Documentation

Regarding plugins, some users utilize the CSF frontend for MailScanner:

ConfigServer MailScanner Front-End for cPanel

Thank you.

 

[smatt]

It depends on the volume of email utilized by the additional email accounts

Server is receiving approximately 4500 a day, sending about 5000 currently. Quite a lot of them are system messages directly to me.

Most, if not all, of the accounts have good DKIM and SPF set up so the sender score is rated quite highly.

Our reservation is as mentioned, because of the shared hostname, if the 600-mailbox org spews out a load of spam it could compromise the other clients.

 

[cPanelMichael]

Our reservation is as mentioned, because of the shared hostname, if the 600-mailbox org spews out a load of spam it could compromise the other clients.

In addition to forcing the emails for that domain name to send through a dedicated IP address, the following document should also help to prevent outgoing SPAM:

How to Prevent Email Abuse - cPanel Knowledge Base - cPanel Documentation

Thank you.

 

[smatt]

Thanks Michael. Going through all the various docs we can find on this to tick as many boxes as possible.

The last piece of the puzzle is to configure Exim to change the SMTP banners depending on the IP and it's associated account. Each IP will have it's own PTR so the banner should reflect that as well. I've seen some info on it but it is largely very old. Is there anything inherent in WHM to do this or modifying the Exim config still the way to go?

Easy FIX your SMTP banner, SMTP greeting and Reverse DNS for Dedicated IPs


Edited for clarification

 

[cPanelMichael]

Is there anything inherent in WHM to do this or modifying the Exim config still the way to go?

Hello,

You will need to use the instructions in the referenced thread to modify the Exim configuration. Feel free to vote and add feedback to the existing feature request for this at:

cPanel & WHM mangment of SMTP Banner for Dedicated IP Accounts

Thank you.