Generally you see catchall domains like this set up by small businesses in conjunction with something like Microsoft SBS/Exchange, vpop or (shudder) mdaemon. Or of course on Linux you could use fetchmail.
Then the collecting system parses the host part of the address and uses it to determine which local mailbox to deliver it to.
I've not seen it done like that at login, usually there is a catchall mail forwarding rule delivering to a single mailbox. It mostly started appearing pre ADSL when small businesses had a dial on demand ISDN connection so couldn't point their MX record at a local SMTP server.
Yes it does become a bit of a spam trap, but usually it ends up being configured to simply delete any mail that doesn't have an associated mailbox. So spam costs you bandwidth.
It also has other issues (so much so in fact Microsoft have dropped this functionality from SBS 2008) in that one oversize message can block the whole mailflow, issues with dealing with bcc and (in Microsoft's case) generating multiple copies if a mail is cc'ed to multiple internal mailboxes, mostly because most of the collectors (inc fetchmail without the right compile time options) don't support envelope.
It has the slight advantage over a pop mailbox per user at the domain end in that extra mailboxes can be added for new users etc without configuration at the hosted end, also some hosting providers charge per mailbox so this was a convenient way to avoid being billed more as your userbase (and hence addresses) grew.
Like I say it is really best avoided but I have plenty of clients that still use this setup.
Peter Alcibiades wrote:
Helping a friend change computers, we found that the email login did not work, and after a series of conversations with the provider were told to log in to get messages using
*@mydomain.com
This did indeed work, and the effect appears to be that mail sent to any name at mydomain.com is picked up by the login, and also that any name used results in mail being accepted. So for instance you can apparently send to
alexander@mydomain.com bacchus@mydomain.com calypso@mydomain.com
and so on, and it will all arrive when you log in for messages as *@mydomain.com.
Why would anyone set up an email system like this? Does it not make a lot more sense to have specific email addresses, both to reduce spam, and to allow you to segregate, for instance, home and business email?
This is the same case where there was the incomprehensible networking with two cards and class B addresses for a three machine network. When set up in the usual way with a five port router modem, it all worked perfectly fine with a lot fewer cables. Very strange.
Peter
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