[Dovecot] best choice of user database file to work with?postfix?

[Thomas Leuxner]

On Thu, Apr 22, 2010 at 01:12:24PM +0200, Rainer Frey wrote:
> Do you define all valid recipients there (e.g. in you example virtual file 
> login at domain.tld)?

Yes.

> But this is at the delivery stage, when the mail has already been accepted. 
> This means, if no homedir/mailbox is found, bounce mails are sent, to 
> potentially forged senders. That is backscatter.
> 
> I'm not talking about aliases, I'm talking about recipient addresses of 
> virtual mailboxes. You need to verify whether a mailbox exists for a recipient 
> address in the SMTP server before accepting the message.

Possibly. But this could then be fixed by adding another recipient
restriction, is that what is bothering you?

> Indeed, but you offered the original poster your solution as one that "should 
> be good enough for what you are trying to achieve", but your solution leaves 
> out the aspect of the valid recipient list for the virtual mailbox domain 
> address class.

This was not meant to say this is the ultimate one and only solution.
See for recipient_restrictions esspecially, everyone may have different
needs. But at least someone *may* a starting point. Feel free to refine
the setup.

> Of course, but it would be a viable alternative to a lookup table for the 
> recipients.

Will look into it, but maybe you can add your thoughts how you would do.

Thomas