Robustifying e-mail

Most e-mail sent is spam, and making sure e-mail reaches its intended recipients keeps getting harder.

Single server installations

When running only a single NAV-instance, sending cron e-mail and alerts and perhaps receiving on mailin@HOSTNAME, the instance needs to be treated like any other e-mail sending server. Set up SPF and preferrably also DKIM.

Multi server installations

If there are multiple instances of NAV working in tandem we recommend sending the e-mail out via a smarthost and standardising on a single domain, for instance nav.YOURDOMAIN and setting up SPF/DKIM for that domain.

For cron, change the localpart (the bit before the @) to contain enough of the hostname so that you can see what instance sent the e-mail, for instance: This is best done by running an e-mail server on the instance to do the rweriting, before sending the e-mail on to the smarthost.

For alerts, this should not be necessary as long as the template mentions which host sent the alert. Just send from a single e-mail address.

For mailin, if you have an e-mail server listening on nav.YOURDOMAIN you can set up an e-mail router with aliases back to the mailin-address on the actual instance if the address you register with the senders are unique per instance (e.g. in an aliases-file):


If you do not switch to a single domain for all the instances you will have to set up SPF/DKIM per hostname.