The document provides troubleshooting steps for resolving issues with cPanel not receiving emails. It suggests checking domain status, email quota, cPanel quota, and email settings, as well as examining bounceback emails and MX records for connectivity issues. If problems persist, contacting customer support is recommended for further assistance.

1. Is Your Cpanel Not Receiving
Emails-What to Do?
There can be many reasons which might be the cause behind
your Cpanel not receiving emails. However, we have listed a few
steps that include simple and complex or basic and advanced
steps to help you get your email function properly again and start
receiving emails again.
Steps to Check if Your Cpanel is Not
Receiving Emails
1. Check Domain Status
Basic step, but good to check it once. To receive emails, you
should make sure that your Domain is active. You can check your
Domain status at WHOIS. If your domain is expired, renew it to
receive emails.
2. Email Quota
Every email address is allotted a fixed quota or amount of disk
space. It might be the case that your email quota is fulfilled and
that’s what stops your account to receive more emails.
There can be two options, either you can change the quota limit
of your email or clear up some disk space i.e. to delete a few
unnecessary emails. Either way, you will get some free space for
your email account and hopefully, you will start receiving emails.
To check the disk space, you can tap on the email icon in Cpanel.
And to increase the size of the email quota, you can refer to
the following steps:

2.  Login to the Cpanel.
 Go to the Email section.
 Click on the Email Accounts icon.

3. Next to your email address, you will find ‘Change Quota’.
Click on that.Type the new limit or set it to unlimited and
then click on ‘Change Quota’.
3. Cpanel Quota

4. Another reason for Cpanel not receiving email may be that the
whole Cpanel has exceeded its quota limit. Simple to fix it.
Increase the disk space allotted.
To check and change the Cpanel quota, you can refer to these
steps:
 In the left-side menu, you will find the ‘Account Information’
section. Go to that.
 Select ‘Show Accounts over quota.’

5.  Here, the account quota can be adjusted, and also you can
view the disk space used.

6.  Once done with changes, click on the ‘Save’ button.
4. Email Bounceback
If you are not receiving any mail, then there is a high chance
that a bounceback email must be getting received by the people
who are trying to send you an email. The bounceback email
probably states the reason why a particular email address is not
able to receive emails.
So, you can try sending an email to your email address from
another address and see what bounceback message you receive.
It might help you to analyze the fault.
5. MX Records
MX records serve as a bridge between Domain and Email
accounts. With your domain being active, you must check if the
MX records are connected to the preferred host.
You can use WhatsmyDNS for it. It can help you get a better
idea of your DNS server and related issues.

7. 6. Mail Settings
Check email settings once to make sure you are not having any
trouble there. Also, if you use the same hosting provider for your
Email and website then set your mail server as ‘Local’. And, if
you are using a different hosting provider, set your mail server to
‘Remote”
Hopefully, one of these solutions will help you solve your problem.
If nothing helps to solve your problem and you are still facing the
issue of not receiving emails, you must contact customer support.
Try contacting the hosting provider’s support for assistance.
Source
https://www.hostitsmart.com/manage/knowledgebase/223/Is-
Your-Cpanel-Not-Receiving-Emails-What-to-Do.html