[Dovecot] Sieve/pigeonhole rejects email addresses for valid UNIX users

[Gábor Lénárt]

Hi,

On Wed, Aug 22, 2012 at 09:56:04AM +0300, David Anderson wrote:
> Self-explanatory, I hope (note the period on the end of the
> username); sieve/pigeonhole does not allow you to have senders which
> end with a period, which means that any UNIX users with such
> usernames who send mail have it rejected by sieve:
> 
> # useradd testuser.
> # su - testuser.
> $ mail david at example.com -s 'testing'
> 123
> .
> [testuser. at levi ~]$ logout
> 
> # less /var/log/maillog
> 
> Aug 22 07:50:56 levi dovecot: lda(david at example.com): Error: sieve:
> envelope sender address 'testuser. at myhost.example.com' is unparsable

Afaik local-part can't have period as the first or the last character by
RFC ... But correct me if I am wrong. At least according to wikipedia:

The local-part of the email address may use any of these ASCII characters
RFC 5322 Section 3.2.3, RFC 6531 permits Unicode beyond the ASCII range:
[...]
Character . (dot, period, full stop) (ASCII: 46) provided that it is not the
first or last character, and provided also that it does not appear two or
more times consecutively (e.g. John..Doe at example.com is not allowed.).

http://en.wikipedia.org/wiki/Email_address#Local_part

I think nowdays it's a bit outdated to have 1:1 mapping between UNIX users
and email addresses anyway. Maybe it's OK, but it's surely problematic in
case of mass hosting with many users with policies like you mentioned as
well. Virtual users (in the sense of MTA/IMAP/etc servers) are much better
idea, in my oppinion. It's OK for a small "server" used for own purposes for
example. But it's only my opinion ...