dovecot - Aug 2017 - unexpected delivery location

Hi,

We're running dovecot 2.2.13, virtual users, with postfix. We have an 
olddomain and a new domainname. To 'translate' *@olddomain into 
*@newdomain, I have configured:
> cat /etc/postfix/canonical
> @olddomain.com   @newdomain.com
While this seems to work, lately we have noticed that dovecot 
occasionally creates mailboxes for non-existent users,
like:
> /var/vmail/...username
> /var/vmail/20username
This only seems to be happening for mails sent to *olddomain*

Looking at the source of these mails, they are indeed sent to 
20username at olddomain.com and ...username at olddomain.com

Mail headers sample:
> Delivered-To: 20username at newdomain.com
> Received: from server1.newdomain.com (server2.newdomain.com [x.y.z.q])
>         by server3.newdomain.com (Postfix) with ESMTPS id 067B4812CF29E
>         for <20username at olddomain.com>; Thu, 13 Jul 2017 19:05:02
+0200 (CEST)
Why doesn't the emailadress 20username at newdomain.com in the above 
generate an error, but instead are delivered to a newly created mailbox?

My feeling is that something is wrong with the way I created the alias 
for olddomain -> newdomain with the canonical-file . Does that make sense?

Our goal is to accept *@olddomain.com like it was sent to 
*@newdomain.com, including delivery failures for nonexistent mailboxes 
like 20username

We configured postfix like:
> canonical_maps = hash:/etc/postfix/canonical
> virtual_alias_maps = ldap:/etc/postfix/ad-mailboxes.cf,
ldap:/etc/postfix/ad-groups.cf
> virtual_uid_maps = static:5000
> virtual_gid_maps = static:5000
> virtual_transport = dovecot
Verified that this config works for newdomain, using:
> root at mail:/etc/postfix# postmap -q alias at newdomain.com 
ldap:/etc/postfix/ad-mailboxes.cf
> userid at newdomain.com
> root at mail:/etc/postfix# postmap -q alias at olddomain.com 
ldap:/etc/postfix/ad-mailboxes.cf
> root at mail:/etc/postfix# 
olddomain gives no result.

Then, from master.cf:
> dovecot unix - n n - - pipe
>   flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/dovecot-lda -f
${sender} -a ${recipient} -d ${user}@${nexthop}
Finally, the mail location as defined in dovecot:
> mail_location = maildir:/var/vmail/%Ln/Maildir:LAYOUT=fs:DIRNAME=mAildir
So, can anyone explain why for mails to olddomain, dovecot creates new 
mailboxes, instead of simply generating an error?

Hi,

Not sure what the lack of replies means... As postfix is also involved, 
should I better ask there?

It seems a little bit in between postfix and dovecot...

Just to clearify one thing I wrote:

On 22-8-2017 16:23, lists wrote:
> We're running dovecot 2.2.13, virtual users, with postfix. We have an 
> olddomain and a new domainname. To 'translate' *@olddomain into 
With "translate" I mean that olddomain should be treated as if it were
newdomain. No translation, but more like an alias.

MJ

On 8/23/2017 4:30 AM, lists wrote:
> Hi,
>
> Not sure what the lack of replies means... As postfix is also
> involved, should I better ask there?
>
> It seems a little bit in between postfix and dovecot...
>
> Just to clearify one thing I wrote:
>
> On 22-8-2017 16:23, lists wrote:
>> We're running dovecot 2.2.13, virtual users, with postfix. We
>> have an olddomain and a new domainname. To 'translate'
>> *@olddomain into 
>
> With "translate" I mean that olddomain should be treated as if it
> were newdomain. No translation, but more like an alias.
>
> MJ

Don't use wildcard aliases.? They break recipient validation and
cause postfix to accept all addresses.

Instead use 1-1 aliases, such as
user1 at olddomaon? user1 at newdomain
user2 at olddomaon? user2 at newdomain
user3 at olddomaon? user3 at newdomain
...



? -- Noel Jones