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ICMP TTL monitoring

From now on the TTL value of ICMP ping replies is monitored, and an informative alarm is triggered when the value changes. This can be useful information to detect network topology changes. The alarm is cleared when the TTL value remains the same for 1 hour.

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E-mail sub-addressing

We have always supported sub-addressing (or “tagging”) when receiving e-mails, by using the “+” sign. E.g. some.one+mytag@domain.com. When using forwarding using an alias, up till now, this sub-address was replicated to the forwarded destination, e.g. some.one+mytag@domain.com gets forwarded to myemail+mytag@gmail.com.

As from now, this behavior is changed, the sub-address is now stripped from the forwarded destination. E.g. an e-mail to some.one+mytag@domain.com now gets forwarded to myemail@gmail.com. You can still use the sub-address in rules at e.g. Gmail, based on the (original) destination.

This change fixes some issues with forwards to mail-servers that don’t support sub-addressing, such as Microsoft Exchange.

Technically, this is implemented by changing the setting “propagate_unmatched_extensions” in Postfix from “canonical, virtual” to “canonical”.

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Monitoring of spam block-lists on Microsoft SNDS

Microsoft maintains its own block-lists for spam detection: Smart Network Data Services (SNDS).  They are used on Hotmail.com, Live.com, Outlook.com, Office365.com and any custom domain hosted on the Microsoft mail servers.  More information can be found here.

The Zabbix server at mon.foxinnovations.be can now be used to monitor your IP-address on those lists.

The zabbix template is made public on my ZabbixCustomTemplates project on GitHub.