[Sieve] Multiple email recipients, how?

[@lbutlr]

On 22 Nov 2019, at 14:48, Ralph Seichter <abbot at monksofcool.net> wrote:
> * Robert via dovecot:
> 
>> We use a simple system for routing emails to different email users by 
>> postfixing the addresses with the actual user: xxxJohn at domain; 
>> yyyJohn at domain etc all will be delivered to user John.
>> (This way John can invent a new email address on-the-fly and that will 
>> be delivered to his email box.)
> 
> This seems like a strange way achieve flexible email addresses. Are you
> aware of sub-addressing? It has been around for ages, and is supported
> by Dovecot (and Gmail, incidentally).

Seconded, this is the way to go.

> Imagine an existing email account <alice at example.com>. If alice wants to
> use a subadress, she signs up with <alice+foo at example.com>, and Dovecot
> can automatically place incoming mail for that address into INBOX/foo
> (or just INBOX if INBOX/foo does not exist). Alice can use as many
> sub-adresses as she needs without anybody making config changes.

Far too many web monkeys seem to get their email validation coede from the same inept repository somewhere, and return error that “+” is not allowed in email addresses. The larger the company, the more likely they are to be incompetent, so I have setup my dovecot and postfix to use two legal delimiters, + and _

> Frankly, the Sieve-based approach you describe seems pretty complicated
> in comparison.

And prone to failure.

Mallory at example.com
JonMallory at example.com
MalloryJones at example.com

Use address extensions. This is all that is required to setup two delimiters:

/etc/postfix/main.cf
recipient_delimiter = +_

/etc/dovecot/dovecot.conf 
protocol lmtp {
  … 
  recipient_delimiter = +_
}


-- 
Yeah, and I never wanted to kick Albert Einstein in the nuts.