Email mailboxes, Aliases
Editing of aliases and distribution lists is discussed here.
A few definitions and analogies:
Imagine a school where each staff member has a named pigeon hole in the staffroom. With real (snail-)mail, the outside of each envelope has a recipient name and an address. The address is used by the postman to work out which letterbox to deliver the mail to. He does not care about the name at the top. A school may accept mail for multiple different addresses, e.g. Example Primary School as well as Example Junior School. However, whatever the address the mail will be delivered through the same letterbox.
Within the school, someone will sort the incoming mail by looking at the name at the top of the envelope and put the letters into the corresponding pigeon hole - they won't really care what the actual address is on the letter (unless it's completely wrong in which the mail gets sent back). If mail is delivered for a generic name like Head, Headteacher, Head Master, Bursar or Secretary, these will be delivered to a personal pigeon hole. There won't be a separate pigeon hole for each possible name.
Any mail that is to an unknown person will tend to get Not known at this address, return to sender written on the outside and sent back.
The name on the envelope doesn't have to be anything like that written on the letter inside; it is possible for the envelope to be addressed to J. Smith, but the letter to say Dear F. Bloggs. The people delivering the mail don't look at the letter.
Mail within the school doesn't need an address on it, just a name.
Email works in pretty much the same way:
An email address looks like
domain.name says which server the outside world to deliver the email to - it is just like a postal address. A server can accept mail for multiple domains (e.g. school.lea.sch.uk as well as school.org.uk). If the domain is wrong (i.e. wrong address), it will get rejected. Once the server has accepted the delivery of mail, it will look at the name part of the address and see where to deliver the mail to - the server will behave just like the person who sorts the (snail-)mail within the school.
Each user has a mailbox called INBOX where new mail is delivered. This is the equivalent of their pigeon-hole. So at its simplest, the name part of the email address is simply the name of a user on the system who has an INBOX to deliver the mail into.
You can also define aliases or redirects which will say whose INBOX to deliver a certain name to. So, for instance, if the headteacher's username is jsmith, you would want the head@, headmaster@, headteacher@ email address to all deliver to the jsmith INBOX. You certainly would NOT want to force the headteacher to have to check 4 or 5 different mailboxes.
Unlike snail-mail, an alias can deliver mail to more than one mailbox. So governors@ could deliver the same mail to several mailboxes (some of which could be external addresses).
Any email that comes in that is for an unknown user or aliases will get rejected and sent back to the sender. You can also also reject mail to specified addresses with a custom message (such as "Tracy no longer works here, please send all mail regarding finance to email@example.com").
Email is delivered only on the basis of the envelope, the email server will not open the email itself to determine where to deliver it (just like real mail). This means that the To: or Cc: names you see in the mail when you read it might not contain your name - but your name was on the envelope. This is how Bcc: (Blind Carbon Copy) email works.
What this means from a email management point of view
- The outside world must know where to deliver mail to for your domain - this is usually managed by your ISP
- Your email server must be configured to accept mail for all the domain
- When you want to create an email address for a specific person who didn't previously have email, you just need to create a new user - just as you would create a new pigeon hole
- If you want to create an email address to be read by someone who already has a mailbox, just set up an alias - just as you wouldn't create a new pigeon hole if someone changed their job title
- Changing aliases is easy, so they are good to use for generic addresses such as info@ or head@. Redirect these through to specific people. Otherwise when people change job, you'd need to tell everyone about the address change (e.g. what happens if the head leaves, but you've advertised her email address as jsmith@ rather than head@?)
- You can also redirect mail when people have left through to their replacements rather than forcing the newcomer to continue using the old email address (yes, some people really do this!)
- If an email address is no longer valid, you can return the mail to the sender with a custom message