Journaling - Non-Secure POP3 Connections - Oct 2022

Updated December 31, 2025 12:00

Service Update

Availability	3rd April - 19th June 2023
Product(s)	Email Security Cloud Gateway
Who's affected	All users

Overview

As part of Mimecast's commitment to continuous improvement, aligning with best practices, and putting the security of our customers first, we have important updates to share with you regarding your POP3 connections with Mimecast.

What's changing

Mimecast will no longer accept connections to its POP3 mailbox service or POP3 Journal connectors over Port 110.
POP3 Mailbox Access: You will not be able to retrieve or send messages from your POP3 mailbox until the configuration has been updated.
POP3 Journal Connectors: Internal messages will fail to be returned by archive searches or end-user applications (Mimecast for Outlook, Mimecast Personal Portal, etc.). Internal messages will also build up in your internal POP3 journal mailbox.

Customers who fail to update their email client configuration to use Port 995 (POP3S) and utilize TLS for both Mailbox Access and Email Journaling will be unable to retrieve messages from their POP3 mailbox. Additionally, they will be unable to send messages until the configuration has been configured correctly.

Deployment Schedule

Region	Date
CA, JER, USB	Monday 20th March 2023
AU	Monday 3rd April 2023
ZA	Monday 10th April 2023
US	Monday 17th April 2023
UK	Monday 24th April 2023
DE	Monday 19th June 2023

Recommended actions

POP3 Mailbox Access

Customers utilizing POP3 mailboxes must ensure they use the following configuration when connecting to Mimecast’s POP3 service.

Incoming Mail Server - Configured to point at the relevant POP Hostname, connect using Port 995 (POP3S), and enable TLS encryption.

POP3 Journal Connector (Within Mimecast)

Customers using POP3 Journal Connectors will need to carry out the following steps.

Log on to the Mimecast Administration Console.
Navigate to Administration | Services | Journaling.
- Ensure the Port field is set to 995 (POP3S).
- Confirm that the “Encrypted” check box is enabled.

POP3 Journal Connector (Customer Environment)

Ensure the following points are adhered to within the customer's email environment:

Ensure that Outbound connections are made via Port 995
Ensure that Enforce TLS is enabled.