Between the 10th and 11th August 2020 we noticed that all Dedicated and Virtual servers running cPanel version v88.0.13 started to receive multiple versions of the following notification:

The mail provider “Outlook” is no longer on the Common Mail Providers list.

cPanel removed the mail provider “Outlook” from the Common Mail Providers list. Emails received from any IP addresses that are associated with this provider will no longer be exempt from Greylisting.

If you want to continue to trust the IP addresses that are associated with this mail provider, you must add them to the Trusted Hosts list in WHM’s Tweak Settings interface at: https://server-hostname:2087/scripts7/greylist/trusted

For your convenience, the following list contains the IP addresses that are associated with this provider:

40.92.0.0-40.95.255.255

This notice is the result of a request from “manage_greylisting”.

The system generated this notice on Tuesday, August 11, 2020 at 9:19:39 AM UTC.

“Greylist System Changes” notifications are currently configured to have an importance of “Low”. You can change the importance or disable this type of notification in WHM’s Contact Manager at: https://server-hostname:2087/scripts2/editcontact?event=Greylist

Do not reply to this automated message.

The alerts seemed to suggest that all of the following Microsoft mail services would be no longer exempt from email greylisting in cPanel:

• – Hotmail
• – Microsoft Exchange Online
• – Symantec Messagelabs
• – Outlook

 

At the time of writing (11th August) there has been no official word from cPanel as to why these mail providers have been suddenly removed from the list of trusted mail providers.

However, despite receiving these notifications saying that the mail providers have been removed from the common mail providers list we are still seeing them as being present in the list of trusted providers so it could just be a cPanel bug but we wont know for sure until someone from cPanel makes an official statement.

For now we recommend all Dedicated Server and VPS clients sit tight and hold off making any changes until cPanel either confirm it’s a bug or provide us with more information as to why the changes have been made.

The other option would be to disable the Greylisting feature via WHM > Greylisting however this may result in more spam hitting your email inbox. If you are unsure how email greylisting works, please see the official description below:

This interface allows you to configure Greylisting, a service that protects your server against unwanted email or spam. When enabled, the mail server will temporarily reject any email from a sender that the server does not recognize. If the email is legitimate, the originating server tries to send it again after a delay. After sufficient time passes, the server accepts the email.

Greylisting identifies incoming email by triplets. A triplet is a collection of three pieces of data: the IP address, the sender’s address, and the recipient’s address. By deferring unknown triplets, Greylisting filters spam and allows legitimate email a second chance to pass through.

If you are still unsure on how to proceed please don’t hesitate to contact a member of our support team via live chat or support ticket and we will be happy to assist you further.

Update: Shortly after we wrote this blog post cPanel have confirmed that it is indeed a bug and the emails can be ignored.