restrict who can send emails to an email address

[Ken Murchison]

On 08/13/2015 08:04 AM, Eric Luyten wrote:
> On Thu, August 13, 2015 1:53 pm, Sunny wrote:
>> Hi,
>>
>>
>> Is there an option in cyrus that can restrict who can send emails to an
>> email address?
>>
>> e.g
>>
>> the mail alias everyone at mycompany.com contains all the members in the
>> organisation - I would like to restrict who can send emails to
>> everyone at mycompany.com, ideally granular control i.e. boss at mycompany.com
>> pa at mycompany.com or if that's not possible only internal users *@mycompany.com
>> (i.e. no external address is allowed to send to
>> everyone at mycompany.com).
>
> Correcting my earlier post : you could write Sieve rules for that Cyrus
> mailbox that bounce/drop/file messages not carrying a From/Sender in the
> local domain.
>
> Please note that a From/Sender line is easily forged.

You could filter on the envelope from rather than the headers.  The 
envelope could also be forged, just not as easily.

-- 
Kenneth Murchison
Principal Systems Software Engineer
Carnegie Mellon University