Changes

Your SMTP servers are open relays. That means if they were accessible on the internet - Internet, anyone could use them in order to send spam. This would very quickly get your server blacklisted and you'd have a very hard time getting yourself off that blacklist.

'''DomainKeys Identified Mail (DKIM) ''' is one of several popular spam-prevention measures that use encryption to sign messages originating from your server so that receiving servers can verify that the messages really did come from your server (the keys are published in DNS).

An address book has nothing to do with email, even though you might think they are related systems. Typically , an address book is a completely separate system - using either a '''CardDav ''' server (one easy to set up comes with OwnCloud) or an LDAP server. Even tightly integrated services like Microsoft's Active Directory keep the address book separate from the email.

If you think about it - , it's is not really clear what service should be responsible for sending out vacation messages. Your receiving SMTP server? Do you really want your users to be able to control that? The client? It's is probably not running.

It's usually yet another is most likely a separate service. Even though the settings to enable vacation response will usually be next to your other email settings - , they will be controlling a separate system that's hooked into your MTA.

=== Other Stuff Email Features ===

There are countless other features and extensions for email. Not to mention propietary proprietary ones like '''Gmail''', '''Yahoo mail''', '''Office 365''', etc. But having Having mastered the email portion of this course - , on the other hand, allows you will be qualified to evaluate capabilities, design integrated systems, and customise customize the email service for you organization like no regular email user can even attempt to comprehend or understand.