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@example.com -s 'testing' 123 . [testuser.@levi ~]$ logout
# less /var/log/maillog
Aug 22 07:50:56 levi dovecot: lda(david@example.com): Error: sieve: envelope sender address 'testuser.@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@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I think nowdays it's a bit outdated to have 1:1 mapping between UNIX users and email addresses anyway.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 ...