In this guide, you will learn about the Connection Stage Authentication Checks feature, including the following information:
- Connection Stage Authentication Checks Feature
- Feature Availability
Connection Stage Authentication Checks Feature
The Connection Stage Authentication Checks feature run all the authentication checks at the connection stage of the SMTP transaction. Only the global level configurations (authentication restrictions, whitelists) will be honored as the authentication user which is needed to load the user level configurations is not known at the connection stage. These checks are performed on connections to the ports of standard email related services.
- SMTP Submission Ports -- 587, 465
- IMAP Ports -- 143, 993 (MailEnable Only)
- POP3 Ports -- 110, 995 (MailEnable Only)
Previously the authentication checks were only ran after a successful authentication attempt which helped to prevent compromised accounts from being abused to send outbound spam but threat actors could still perform authentication attacks to compromise the account. By blocking connections with authentication checks at the earliest possible stage in the SMTP transaction, threat actors are no longer able to perform authentication attacks to compromise accounts which also reduce server overhead.
SMTP transactions that pass the connection stage authentication checks are still subjected to the authentication checks after a successful authentication attempt. The latter authentication checks loads the user level configurations of email domains for accounts which have been assigned a package with MagicSpam enabled. As such, there can be up to two MagicSpam authentication log entries per SMTP transaction.
Due to limitations with the email server software distributed with certain web panels, you will need to upgrade to specified version to have access to the feature.
- Plesk Obsidian 18.0.23 and above (Postfix only)
- MailEnable 10.35 and above
- Zimbra 9.0.0 Patch 8 and above
This feature is only available on the PLUS and PRO version of MagicSpam, starting from these versions onwards:
- MagicSpam PRO for Plesk 2.1-17.1
- MagicSpam PRO for cPanel 2.1-16.1
- MagicSpam PRO for DirectAdmin 2.1-15.1
- MagicSpam PRO for InterWorx 2.1-5.1
- MagicSpam PLUS for MailEnable 2.1-12.1
- MagicSpam PLUS for Zimbra 2.1-12.1