Subject: Re: Post ACL
From: Alexey Melnikov <[email-masked]>
To: Alexandros Vellis <[email-masked]>
Cc: Timo Sirainen <[email-masked]>, [email-masked]
Date: Mon, 17 Nov 2008 15:56:35 -0600
List-Id: <ietf-imapext.imc.org>

Alexandros Vellis wrote:

>On Sat, 15 Nov 2008 18:22:20 -0600
>Alexey Melnikov <[email-masked]> wrote:
>  
>
>>>If answer to either one is "yes", how are the ACL identifiers
>>>matched?
>>>      
>>>
>>I would treat the MAIL FROM sender as the username, canonicalizing it 
>>first. If the sender has mailbox on the same server, then you can
>>strip plus addressing from it.
>>    
>>
>
>And there is also the possibility of using an additional parameter in
>the MAIL FROM:
>
>RFC 2554 SMTP Service Extension for Authentication
>paragraph 5. The AUTH parameter to the MAIL FROM command
>  
>
Yes.

Date: Mon, 17 Nov 2008 22:48:53 +0200
From: Alexandros Vellis <[email-masked]>
To: Alexey Melnikov <[email-masked]>
Cc: Timo Sirainen <[email-masked]>, [email-masked]
Subject: Re: Post ACL
Organization: National and Kapodistrian University of Athens
Sender: [email-masked]

On Sat, 15 Nov 2008 18:22:20 -0600
Alexey Melnikov <[email-masked]> wrote:

> >If answer to either one is "yes", how are the ACL identifiers
> >matched?
> >  
> >
> I would treat the MAIL FROM sender as the username, canonicalizing it 
> first. If the sender has mailbox on the same server, then you can
> strip plus addressing from it.

And there is also the possibility of using an additional parameter in
the MAIL FROM:

RFC 2554 SMTP Service Extension for Authentication
paragraph 5. The AUTH parameter to the MAIL FROM command

-- 
Alexandros Vellis
National and Kapodistrian University of Athens
Network Operations Centre

Date: Sun, 16 Nov 2008 06:43:29 -0600
From: Alexey Melnikov <[email-masked]>
To: Timo Sirainen <[email-masked]>
CC: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

Timo Sirainen wrote:

>On Sat, 2008-11-15 at 18:22 -0600, Alexey Melnikov wrote:
>  
>
>>Timo Sirainen wrote:
>>    
>>
>>>>p - post (send mail to submission address for mailbox,
>>>>      not enforced by IMAP4 itself)
>>>>        
>>>>
>>>What exactly does this mean?
>>>      
>>>
>Are there any other uses for 'p' other than what I mentioned?
>  
>
I can't think of any other use cases.

>>>If answer to either one is "yes", how are the ACL identifiers matched?
>>>      
>>>
>>I would treat the MAIL FROM sender as the username, canonicalizing it 
>>first. 
>>    
>>
>And your server really is already doing that? :)
>  
>
No, because our server doesn't support the "p" right :-).

>>If the sender has mailbox on the same server, then you can strip 
>>plus addressing from it.
>>    
>>
>I'm not really sure what you mean by this. Strip plus addressing from
>the MAIL FROM address?
>  
>
I meant if the sender is [email-masked] (where example.com is 
a domain "owned" by the message store), then this would become 
[email-masked] before the ACL check is done.

Cc: [email-masked]
From: Timo Sirainen <[email-masked]>
To: Philip Guenther <[email-masked]>
Subject: Re: Post ACL
Date: Sun, 16 Nov 2008 13:17:46 +0200
Sender: [email-masked]

This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--Apple-Mail-4--581036837
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit

On Nov 16, 2008, at 8:29 AM, Philip Guenther wrote:

>> I guess I could create a completely separate "anonymous" user that
>> doesn't match any other user. Then each mailbox could have by  
>> default an
>> "anonymous +p" right (it would match non-INBOX only when using  
>> +detail
>> addresses).
>
> Given that you have per-user filters and can get authentication from  
> that,
> why would you supply a default "anonymous +p" right at all?

Not everyone are using per-user filters. Or filtering at all.

> Assuming
> there's a case where it's necessary, are you sure it's needed for
> mailboxes other than INBOX?

I was thinking about the people who are using user+mailbox@domain  
style addressing (and no filtering). Perhaps they'd want to use ACLs  
to restrict for which mailboxes delivery isn't allowed. The normal  
case seems to be that they want delivery to work to most of their  
mailboxes, but maybe there are some exception mailboxes such as Drafts  
or Sent Messages.

Of course maybe I could just ignore these people and assume they don't  
want to use ACLs at all. :) It would make the implementation easier.

--Apple-Mail-4--581036837
content-type: application/pgp-signature; x-mac-type=70674453;
	name=PGP.sig
content-description: This is a digitally signed message part
content-disposition: inline; filename=PGP.sig
content-transfer-encoding: 7bit

--Apple-Mail-4--581036837--

Date: Sat, 15 Nov 2008 22:29:51 -0800
From: Philip Guenther <[email-masked]>
To: Timo Sirainen <[email-masked]>
cc: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

On Sun, 16 Nov 2008, Timo Sirainen wrote:
...
> I'm not entirely sure about the default 'p' right though. If I give 
> "anyone +p" right it would mean that user1's Sieve script could do 
> fileinto "shared/user2/INBOX", which doesn't seem like a good idea.

I agree: having a default "anyone +p" is unnecessary and 
counter-productive when the system has filters to provide fine-grained 
access-control.

> I guess I could create a completely separate "anonymous" user that 
> doesn't match any other user. Then each mailbox could have by default an 
> "anonymous +p" right (it would match non-INBOX only when using +detail 
> addresses).

Given that you have per-user filters and can get authentication from that, 
why would you supply a default "anonymous +p" right at all?  Assuming 
there's a case where it's necessary, are you sure it's needed for 
mailboxes other than INBOX?

Philip Guenther

Cc: [email-masked]
From: Timo Sirainen <[email-masked]>
To: Philip Guenther <[email-masked]>
Subject: Re: Post ACL
Date: Sun, 16 Nov 2008 06:31:04 +0200
Sender: [email-masked]

This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--Apple-Mail-3--605438735
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit

On Nov 16, 2008, at 5:56 AM, Philip Guenther wrote:

>> If answer to either one is "yes", how are the ACL identifiers  
>> matched?
>
> Unspecified and implementation dependent, but that's true of  
> basically all
> authentication ID handling in IMAP, no?

Sure, I was just trying to figure out some reasonable way to implement  
it.

> How I eventually ended up handling this in Sendmail's product was  
> roughly
> as follows:
> - if delivery was specified by an action in a user's sieve filter,  
> the ACL
>  check would be as that user
> - if a user didn't have a sieve filter then, by default, delivery  
> will be
>  to the user's INBOX (+detail will be ignored) and will be permitted
>  regardless of the mailbox's ACL
>  - alternatively, it can be configured to pass through +detail info
>    and check for anonymous having 'p' right when a +detail is supplied
> - delivery that's specified by an adminstrative filter generally skips
>  the ACL check

Thanks, this sounds good. I'll probably implement it the same way.

I'm not entirely sure about the default 'p' right though. If I give  
"anyone +p" right it would mean that user1's Sieve script could do  
fileinto "shared/user2/INBOX", which doesn't seem like a good idea. I  
guess I could create a completely separate "anonymous" user that  
doesn't match any other user. Then each mailbox could have by default  
an "anonymous +p" right (it would match non-INBOX only when using  
+detail addresses).

--Apple-Mail-3--605438735
content-type: application/pgp-signature; x-mac-type=70674453;
	name=PGP.sig
content-description: This is a digitally signed message part
content-disposition: inline; filename=PGP.sig
content-transfer-encoding: 7bit

--Apple-Mail-3--605438735--

Date: Sat, 15 Nov 2008 19:56:27 -0800
From: Philip Guenther <[email-masked]>
To: Timo Sirainen <[email-masked]>
cc: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

On Sat, 15 Nov 2008, Timo Sirainen wrote:
> > p - post (send mail to submission address for mailbox,
> >        not enforced by IMAP4 itself)
> 
> What exactly does this mean?

That depends on what mail store supports.  If the mail store doesn't have 
any means of injecting messages other than IMAP, then it means nothing.  
If it supports injection of messages to specific mailboxes via SMTP/LMTP, 
then the 'p' right should be used in deciding whether a given injection 
should be permitted.  How it selects an ACL entry (i.e., which authid to 
act as) and whether there are exceptional situations is unspecified and 
therefore implementation dependent.

For example, I would expect most mail stores to permit anonymous delivery 
to a user's INBOX by default, perhaps via a general rule ("don't check the 
ACL for plain <user@domain> delivery") or by initially giving each user's 
INBOX an ACL that gives 'anonymous' the 'p' right.  Alternatively, a 
system that supported filtering via Sieve might treat a user's filter as 
the 'authenticated agent', so that a message delivered via a 'keep' would 
involve checking the ACL as that user instead of as anonymous.

> 1) Assume user+mailbox@domain style addresses are used. Should MDA check 
> the ACLs before allowing delivery to the mailbox?

Sure.

> 2) Should Sieve fileinto check the ACL before it's allowed?

Sure.  I would expect that check to use the identity of the sieve script 
'owner' for that check, where such an identity can be established.

> If answer to either one is "yes", how are the ACL identifiers matched?

Unspecified and implementation dependent, but that's true of basically all 
authentication ID handling in IMAP, no?

How I eventually ended up handling this in Sendmail's product was roughly 
as follows:
- if delivery was specified by an action in a user's sieve filter, the ACL
  check would be as that user
- if a user didn't have a sieve filter then, by default, delivery will be
  to the user's INBOX (+detail will be ignored) and will be permitted
  regardless of the mailbox's ACL
  - alternatively, it can be configured to pass through +detail info
    and check for anonymous having 'p' right when a +detail is supplied
- delivery that's specified by an adminstrative filter generally skips
  the ACL check

Philip Guenther

Subject: Re: Post ACL
From: Timo Sirainen <[email-masked]>
To: Alexey Melnikov <[email-masked]>
Cc: [email-masked]
Date: Sun, 16 Nov 2008 02:49:52 +0200
Sender: [email-masked]

--=-Qihs+FcmjXsylMCr52fL
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable

On Sat, 2008-11-15 at 18:22 -0600, Alexey Melnikov wrote:
> Timo Sirainen wrote:
>=20
> >>p - post (send mail to submission address for mailbox,
> >>       not enforced by IMAP4 itself)
> >>   =20
> >>
> >What exactly does this mean?

Are there any other uses for 'p' other than what I mentioned?

> >If answer to either one is "yes", how are the ACL identifiers matched?
> =20
> I would treat the MAIL FROM sender as the username, canonicalizing it=20
> first.=20

And your server really is already doing that? :)

> If the sender has mailbox on the same server, then you can strip=20
> plus addressing from it.

I'm not really sure what you mean by this. Strip plus addressing from
the MAIL FROM address?

--=-Qihs+FcmjXsylMCr52fL
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part

--=-Qihs+FcmjXsylMCr52fL--

Date: Sat, 15 Nov 2008 18:22:20 -0600
From: Alexey Melnikov <[email-masked]>
To: Timo Sirainen <[email-masked]>
CC: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

Timo Sirainen wrote:

>>p - post (send mail to submission address for mailbox,
>>       not enforced by IMAP4 itself)
>>    
>>
>What exactly does this mean?
>
>1) Assume user+mailbox@domain style addresses are used. Should MDA check
>the ACLs before allowing delivery to the mailbox?
>  
>
It might :-). But it needs to map all senders that MDA don't recognize 
to anonymous.

>2) Should Sieve fileinto check the ACL before it's allowed?
>
I guess that should work in the same way.

>If answer to either one is "yes", how are the ACL identifiers matched?
>  
>
I would treat the MAIL FROM sender as the username, canonicalizing it 
first. If the sender has mailbox on the same server, then you can strip 
plus addressing from it.

Subject: Post ACL
From: Timo Sirainen <[email-masked]>
To: [email-masked]
Date: Sat, 15 Nov 2008 22:28:18 +0200
Sender: [email-masked]

--=-9kfmXAW1N0IomzCYqyae
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable

> p - post (send mail to submission address for mailbox,
>        not enforced by IMAP4 itself)

What exactly does this mean?

1) Assume user+mailbox@domain style addresses are used. Should MDA check
the ACLs before allowing delivery to the mailbox?

2) Should Sieve fileinto check the ACL before it's allowed?

If answer to either one is "yes", how are the ACL identifiers matched?

--=-9kfmXAW1N0IomzCYqyae
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part

--=-9kfmXAW1N0IomzCYqyae--

Date: Mon, 17 Nov 2008 15:56:35 -0600
From: Alexey Melnikov <[email-masked]>
To: Alexandros Vellis <[email-masked]>
CC: Timo Sirainen <[email-masked]>, [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

Alexandros Vellis wrote:

>On Sat, 15 Nov 2008 18:22:20 -0600
>Alexey Melnikov <[email-masked]> wrote:
>  
>
>>>If answer to either one is "yes", how are the ACL identifiers
>>>matched?
>>>      
>>>
>>I would treat the MAIL FROM sender as the username, canonicalizing it 
>>first. If the sender has mailbox on the same server, then you can
>>strip plus addressing from it.
>>    
>>
>
>And there is also the possibility of using an additional parameter in
>the MAIL FROM:
>
>RFC 2554 SMTP Service Extension for Authentication
>paragraph 5. The AUTH parameter to the MAIL FROM command
>  
>
Yes.

Date: Mon, 17 Nov 2008 22:48:53 +0200
From: Alexandros Vellis <[email-masked]>
To: Alexey Melnikov <[email-masked]>
Cc: Timo Sirainen <[email-masked]>, [email-masked]
Subject: Re: Post ACL
Organization: National and Kapodistrian University of Athens
Sender: [email-masked]

On Sat, 15 Nov 2008 18:22:20 -0600
Alexey Melnikov <[email-masked]> wrote:

> >If answer to either one is "yes", how are the ACL identifiers
> >matched?
> >  
> >
> I would treat the MAIL FROM sender as the username, canonicalizing it 
> first. If the sender has mailbox on the same server, then you can
> strip plus addressing from it.

And there is also the possibility of using an additional parameter in
the MAIL FROM:

RFC 2554 SMTP Service Extension for Authentication
paragraph 5. The AUTH parameter to the MAIL FROM command

-- 
Alexandros Vellis
National and Kapodistrian University of Athens
Network Operations Centre

Date: Sun, 16 Nov 2008 06:43:29 -0600
From: Alexey Melnikov <[email-masked]>
To: Timo Sirainen <[email-masked]>
CC: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

Timo Sirainen wrote:

>On Sat, 2008-11-15 at 18:22 -0600, Alexey Melnikov wrote:
>  
>
>>Timo Sirainen wrote:
>>    
>>
>>>>p - post (send mail to submission address for mailbox,
>>>>      not enforced by IMAP4 itself)
>>>>        
>>>>
>>>What exactly does this mean?
>>>      
>>>
>Are there any other uses for 'p' other than what I mentioned?
>  
>
I can't think of any other use cases.

>>>If answer to either one is "yes", how are the ACL identifiers matched?
>>>      
>>>
>>I would treat the MAIL FROM sender as the username, canonicalizing it 
>>first. 
>>    
>>
>And your server really is already doing that? :)
>  
>
No, because our server doesn't support the "p" right :-).

>>If the sender has mailbox on the same server, then you can strip 
>>plus addressing from it.
>>    
>>
>I'm not really sure what you mean by this. Strip plus addressing from
>the MAIL FROM address?
>  
>
I meant if the sender is [email-masked] (where example.com is 
a domain "owned" by the message store), then this would become 
[email-masked] before the ACL check is done.

Cc: [email-masked]
From: Timo Sirainen <[email-masked]>
To: Philip Guenther <[email-masked]>
Subject: Re: Post ACL
Date: Sun, 16 Nov 2008 13:17:46 +0200
Sender: [email-masked]

This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--Apple-Mail-4--581036837
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit

On Nov 16, 2008, at 8:29 AM, Philip Guenther wrote:

>> I guess I could create a completely separate "anonymous" user that
>> doesn't match any other user. Then each mailbox could have by  
>> default an
>> "anonymous +p" right (it would match non-INBOX only when using  
>> +detail
>> addresses).
>
> Given that you have per-user filters and can get authentication from  
> that,
> why would you supply a default "anonymous +p" right at all?

Not everyone are using per-user filters. Or filtering at all.

> Assuming
> there's a case where it's necessary, are you sure it's needed for
> mailboxes other than INBOX?

I was thinking about the people who are using user+mailbox@domain  
style addressing (and no filtering). Perhaps they'd want to use ACLs  
to restrict for which mailboxes delivery isn't allowed. The normal  
case seems to be that they want delivery to work to most of their  
mailboxes, but maybe there are some exception mailboxes such as Drafts  
or Sent Messages.

Of course maybe I could just ignore these people and assume they don't  
want to use ACLs at all. :) It would make the implementation easier.

--Apple-Mail-4--581036837
content-type: application/pgp-signature; x-mac-type=70674453;
	name=PGP.sig
content-description: This is a digitally signed message part
content-disposition: inline; filename=PGP.sig
content-transfer-encoding: 7bit

--Apple-Mail-4--581036837--

Date: Sat, 15 Nov 2008 22:29:51 -0800
From: Philip Guenther <[email-masked]>
To: Timo Sirainen <[email-masked]>
cc: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

On Sun, 16 Nov 2008, Timo Sirainen wrote:
...
> I'm not entirely sure about the default 'p' right though. If I give 
> "anyone +p" right it would mean that user1's Sieve script could do 
> fileinto "shared/user2/INBOX", which doesn't seem like a good idea.

I agree: having a default "anyone +p" is unnecessary and 
counter-productive when the system has filters to provide fine-grained 
access-control.

> I guess I could create a completely separate "anonymous" user that 
> doesn't match any other user. Then each mailbox could have by default an 
> "anonymous +p" right (it would match non-INBOX only when using +detail 
> addresses).

Given that you have per-user filters and can get authentication from that, 
why would you supply a default "anonymous +p" right at all?  Assuming 
there's a case where it's necessary, are you sure it's needed for 
mailboxes other than INBOX?

Philip Guenther

Cc: [email-masked]
From: Timo Sirainen <[email-masked]>
To: Philip Guenther <[email-masked]>
Subject: Re: Post ACL
Date: Sun, 16 Nov 2008 06:31:04 +0200
Sender: [email-masked]

This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--Apple-Mail-3--605438735
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit

On Nov 16, 2008, at 5:56 AM, Philip Guenther wrote:

>> If answer to either one is "yes", how are the ACL identifiers  
>> matched?
>
> Unspecified and implementation dependent, but that's true of  
> basically all
> authentication ID handling in IMAP, no?

Sure, I was just trying to figure out some reasonable way to implement  
it.

> How I eventually ended up handling this in Sendmail's product was  
> roughly
> as follows:
> - if delivery was specified by an action in a user's sieve filter,  
> the ACL
>  check would be as that user
> - if a user didn't have a sieve filter then, by default, delivery  
> will be
>  to the user's INBOX (+detail will be ignored) and will be permitted
>  regardless of the mailbox's ACL
>  - alternatively, it can be configured to pass through +detail info
>    and check for anonymous having 'p' right when a +detail is supplied
> - delivery that's specified by an adminstrative filter generally skips
>  the ACL check

Thanks, this sounds good. I'll probably implement it the same way.

I'm not entirely sure about the default 'p' right though. If I give  
"anyone +p" right it would mean that user1's Sieve script could do  
fileinto "shared/user2/INBOX", which doesn't seem like a good idea. I  
guess I could create a completely separate "anonymous" user that  
doesn't match any other user. Then each mailbox could have by default  
an "anonymous +p" right (it would match non-INBOX only when using  
+detail addresses).

--Apple-Mail-3--605438735
content-type: application/pgp-signature; x-mac-type=70674453;
	name=PGP.sig
content-description: This is a digitally signed message part
content-disposition: inline; filename=PGP.sig
content-transfer-encoding: 7bit

--Apple-Mail-3--605438735--

Date: Sat, 15 Nov 2008 19:56:27 -0800
From: Philip Guenther <[email-masked]>
To: Timo Sirainen <[email-masked]>
cc: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

On Sat, 15 Nov 2008, Timo Sirainen wrote:
> > p - post (send mail to submission address for mailbox,
> >        not enforced by IMAP4 itself)
> 
> What exactly does this mean?

That depends on what mail store supports.  If the mail store doesn't have 
any means of injecting messages other than IMAP, then it means nothing.  
If it supports injection of messages to specific mailboxes via SMTP/LMTP, 
then the 'p' right should be used in deciding whether a given injection 
should be permitted.  How it selects an ACL entry (i.e., which authid to 
act as) and whether there are exceptional situations is unspecified and 
therefore implementation dependent.

For example, I would expect most mail stores to permit anonymous delivery 
to a user's INBOX by default, perhaps via a general rule ("don't check the 
ACL for plain <user@domain> delivery") or by initially giving each user's 
INBOX an ACL that gives 'anonymous' the 'p' right.  Alternatively, a 
system that supported filtering via Sieve might treat a user's filter as 
the 'authenticated agent', so that a message delivered via a 'keep' would 
involve checking the ACL as that user instead of as anonymous.

> 1) Assume user+mailbox@domain style addresses are used. Should MDA check 
> the ACLs before allowing delivery to the mailbox?

Sure.

> 2) Should Sieve fileinto check the ACL before it's allowed?

Sure.  I would expect that check to use the identity of the sieve script 
'owner' for that check, where such an identity can be established.

> If answer to either one is "yes", how are the ACL identifiers matched?

Unspecified and implementation dependent, but that's true of basically all 
authentication ID handling in IMAP, no?

How I eventually ended up handling this in Sendmail's product was roughly 
as follows:
- if delivery was specified by an action in a user's sieve filter, the ACL
  check would be as that user
- if a user didn't have a sieve filter then, by default, delivery will be
  to the user's INBOX (+detail will be ignored) and will be permitted
  regardless of the mailbox's ACL
  - alternatively, it can be configured to pass through +detail info
    and check for anonymous having 'p' right when a +detail is supplied
- delivery that's specified by an adminstrative filter generally skips
  the ACL check

Philip Guenther

Subject: Re: Post ACL
From: Timo Sirainen <[email-masked]>
To: Alexey Melnikov <[email-masked]>
Cc: [email-masked]
Date: Sun, 16 Nov 2008 02:49:52 +0200
Sender: [email-masked]

--=-Qihs+FcmjXsylMCr52fL
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable

On Sat, 2008-11-15 at 18:22 -0600, Alexey Melnikov wrote:
> Timo Sirainen wrote:
>=20
> >>p - post (send mail to submission address for mailbox,
> >>       not enforced by IMAP4 itself)
> >>   =20
> >>
> >What exactly does this mean?

Are there any other uses for 'p' other than what I mentioned?

> >If answer to either one is "yes", how are the ACL identifiers matched?
> =20
> I would treat the MAIL FROM sender as the username, canonicalizing it=20
> first.=20

And your server really is already doing that? :)

> If the sender has mailbox on the same server, then you can strip=20
> plus addressing from it.

I'm not really sure what you mean by this. Strip plus addressing from
the MAIL FROM address?

--=-Qihs+FcmjXsylMCr52fL
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part

--=-Qihs+FcmjXsylMCr52fL--

Date: Sat, 15 Nov 2008 18:22:20 -0600
From: Alexey Melnikov <[email-masked]>
To: Timo Sirainen <[email-masked]>
CC: [email-masked]
Subject: Re: Post ACL
Sender: [email-masked]

Timo Sirainen wrote:

>>p - post (send mail to submission address for mailbox,
>>       not enforced by IMAP4 itself)
>>    
>>
>What exactly does this mean?
>
>1) Assume user+mailbox@domain style addresses are used. Should MDA check
>the ACLs before allowing delivery to the mailbox?
>  
>
It might :-). But it needs to map all senders that MDA don't recognize 
to anonymous.

>2) Should Sieve fileinto check the ACL before it's allowed?
>
I guess that should work in the same way.

>If answer to either one is "yes", how are the ACL identifiers matched?
>  
>
I would treat the MAIL FROM sender as the username, canonicalizing it 
first. If the sender has mailbox on the same server, then you can strip 
plus addressing from it.

Subject: Post ACL
From: Timo Sirainen <[email-masked]>
To: [email-masked]
Date: Sat, 15 Nov 2008 22:28:18 +0200
Sender: [email-masked]

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> p - post (send mail to submission address for mailbox,
>        not enforced by IMAP4 itself)

What exactly does this mean?

1) Assume user+mailbox@domain style addresses are used. Should MDA check
the ACLs before allowing delivery to the mailbox?

2) Should Sieve fileinto check the ACL before it's allowed?

If answer to either one is "yes", how are the ACL identifiers matched?

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