[Discuss] Lost email?

[Daniel Hagerty]

Jack Coats <jack at coats.org> writes:

>    But in the future you might configure a 'secondary email server'.
>    [how to setup a secondary mail server. ]

    With a really important addition for modern mail servers: You
must, must, must ensure that any mail the secondaries accepts will
deliver, without bounce, on the primary.  If bob at example.com is
non-deliverable on the primary, secondaries must reject this recipient
at SMTP layer.

    If this is not true, you will generate backscatter spam, possibly
ending up on blacklists, etc, etc.