Firewall Configuration for Multi Server Mode

It is highly recommended to protect any MailStore Service Provider Edition service with appropriate firewall rules. This document should help with setting up the required rules. The firewall rules for running the SPE in Single Server Mode can be found in this document.

Important Notices:

  • The communication channels described below MUST NOT be intercepted by any kind of email or web proxies that are provided as part of antivirus software or unified threat management gateways.
  • If there are multiple Client Access Servers (CAS) and a load balancer is installed in front of these CAS, the load balancer must be configured in such a way that a user's sessions terminate on the same CAS (sticky sessions).
  • The Windows Advanced Firewall is activated on any Windows Server installation by default. In order to connect to services (e.g. MailStore Management Console) of the MailStore Service Provider Edition, it is required that the appropriate firewall rules are added (see below).

The below table lists all TCP ports that need to be opened in the firewall when using MailStore Service Provider Edition in multi server mode. These are the default ports which may have been altered. The following abbreviations are used in the source and target columns:

  • ANY = Any computer from private or public networks
  • ADM = Computer or network used for administration
  • CAS = Server hosting Client Access Server role
  • IH = Server hosting Instance Host role
  • MGMT = Server hosting Management Server role
  • CA = Certificate Authority
Port Source Target Description
80 ANY CA Access to certificate authorities to check certificate revocation status via HTTP.
110 IH ANY Access to email servers for archiving via POP3 (Unencrypted/STARTTLS).
143 IH ANY Access to email servers for archiving via IMAP (Unencrypted/STARTTLS).
143 ANY CAS IMAP access to archives secured by TLS (STARTTLS) encryption.
389 IH ANY Access to LDAP servers (including Microsoft Active Directory) using an unencrypted or STARTTLS-encrypted session.
443 IH ANY Access to Microsoft Exchange Server for archiving via Exchange Web Services (EWS) secured by SSL encryption.
443 IH ANY Access to IceWarp Mail Servers for synchronizing and authenticating users via API secured by TLS encryption.
443 ANY CAS HTTPS access to instances used by E-mail Archive Client, Outlook Add-in, and MailStore Web Access.
443 MGMT my.mailstore.com Usage reporting and license update. If a system wide proxy has been configured, it will be used.
Important: DNS hostname MUST be used in firewall rules due to periodically changing IP addresses of my.mailstore.com.
587 MGMT ANY Access to an email server to let the Management Server send product update emails.
587 IH ANY Access to an email server to let instances send status reports.
636 IH ANY Access to LDAP servers (including Microsoft Active Directory) using a TLS encrypted connection.
993 ANY CAS IMAP access to archives secured by TLS encryption.
993 IH ANY Access to email servers for archiving via IMAP (TLS).
995 IH ANY Access to email servers for archiving via POP3 (TLS).
4040 IH ANY Access to Kerio Connect Servers for synchronizing users via API secured by TLS encryption.
8470 ADM MGMT Web-based access to the MailStore Management Console.
8471 CAS, IH MGMT Internal communication with Management Server
8472 MGMT, CAS IH Internal communication with Instance Hosts
8473 MGMT CAS Internal communication with Client Access Servers
8474 ADM MGMT Access to the MailStore Management API.
8474 IH, CAS MGMT Optional: Required for initial pairing with Management Server in Multi Server Mode. If not available, manual registration of Instance Hosts and Client Access Servers in Management Server is required.