Message Routing - POP Frequently Asked Questions

This article provides Frequently Asked Questions and summarizes the current best practice following recent improvements. At Mimecast, we are continually extending our architecture and upgrading our core systems to provide greater capacity and improved service availability. One current area of focus is our Post Office Protocol v3 (POP3) services. 

Customers using these services should check the configuration of their mail clients to ensure they are using our latest high-availability distributed POP3 mail gateways. This article answers some of the most common questions about our POP offering.

The Frequently Asked Questions

Q:

Who can use Mimecast's POP services?

A:

We provide POP retrieval for two purposes: For standard retrieval of mail sent to local (i.e., POP-only) internal domains. As a backup mail retrieval method during a continuity event. In the short-term, other customers may be able to retrieve recent mail via POP, but this is a temporary artefact of our current implementation and is not intended functionality. Please contact your Mimecast account manager if you require POP access but have neither a local internal domain nor a Continuity package. In all cases, the customer administrator can control access to POP services by individual address or with the account-level POP Services Override switch.

Q:	What is the use case for POP-only (local) domains?
A:	Small organizations may elect to have their users interact directly with Mimecast, without additional infrastructure (e.g., Microsoft Exchange). In such cases, an administrator can configure a local internal domain that restricts users to receive mail only using POP.

Q:	What is the use case for POP continuity?
A:	If an organization experiences an outage, it may enable its users to temporarily connect to Mimecast via POP for mail retrieval until normal service is restored.

Q:	How can I check the POP status of my account?
A:	Customers subscribing to Continuity services will see a Continuity option under the Services menu in the Administration Console. The status of internal domains can be viewed in the Administration Console: Navigate to Users & Groups | Internal Directories. Right-click on a domain and click Edit Domain to view the Local Mailboxes status. If Local Mailboxes is checked, this is a POP-only domain.

Q:	What is the correct POP configuration?
A:	For eligible customers, full details of the correct configuration can be found in the Knowledge Base. In summary, all POP requests should be via SSL on port 995 to the hostname for your region: Europe: eu-pop.mimecast.com North-America: us-pop.mimecast.com South Africa: za-pop.mimecast.co.za Australia: au-pop.mimecast.com Offshore: je-pop.mimecast.com

Q:	For how long is mail available for POP retrieval?
A:	Mail received for local internal domains remains available for 60 days. POP continuity mailboxes offer the retrieval of mail received over the past 5 days.

Q:	Can I change these periods?
A:	At this time, we do not plan to offer configurable POP retrieval periods.

Q:	Does POP retrieval affect archive retention?
A:	No. Availability for POP retrieval is completely independent of archiving retention. Archiving customers will have all mail archived from the point of receipt in line with their retention configuration.

Q:	Does POP access limit any Secure Email Gateway features?
A:	No. Mimecast applies consistent security policies to all inbound mail.

Q:	How can I obtain more information?
A:	Technical questions about POP configuration should be addressed to the Mimecast Support team. All other questions should be directed to your account manager in the first instance.