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:
root=nav-3rdstreet@nav.example.com
. 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):
mailin=nav-3rdstreet: mailin@nav-3rdstreet.nav.example.com
If you do not switch to a single domain for all the instances you will have to set up SPF/DKIM per hostname.