Click the button below to set up the sendmail scenario.

Add an alias so that all email going to local user jim will instead go to local user frank.

Add an alias so that all email going to local user bob will be silently deleted.

Add an alias so that all email going to local user peter will be sent to both allan and zoe..

Arrange sendmail so that if mail arrives for jim@null.com, it gets sent to the local user frank.

Keeping the previous rule for frank, make sure that all email for the null.com domain which is not jim@null.com gets delivered to local user adam.

Continuing on from the previous rules, now create rules so that when frank SENDS emails, then appear to come from jim@null.com. Additionally, make sure that when adam sends emails, they appear to come from adam@null.com.

User iain has complained that he is not receiving any email, and instead he has heard that victor and victoria are receiving his email instead. Fix this issue for iain.

What would be the entry needed in the DNS information to provide an spf entry so that only the ip 10.0.0.1 was allowed to send emails for the current SOA?

Make sure the rule only contains the settings as indicated above, and make sure that the rule is set with a hard fail. Use all lower case, and only put a single space character between the elements.