new feature: sieve forward plugin

[Marc]

Hi Paul,

I appreciate the huge response! :)


> 
> Ok this in itself is a issue however forwards should be fully received
> by the server and then resent to get around this issue.
> 
> I use the mapping feature & the database to handle forwards in postfix
> which appears to work without any issues bypassing sieve.
>

But this creates a dependency between your dovecot mail server and your outgoing. You should keep things simple.

> #Postgres Stuff

I am using ldap ;)
 
> 
> So when using the above postfix receives it, remaps it and resends the
> email as its own thus fixing any spf issues along the way as it is sent
> by the local server.

Yes always. I do not see anything that distinguishes between senders that have or have not set spf. It is still nice to receive the forwarded message unchanged (think of internal delivery)

> I understand that forwarding in a sieve script might over ride this and
> cause an spf failure, in that case (and i have not tried) then the sieve
> script should somehow deliver local and then resend?

I have no idea, but this code forwards, so it should be possible to change the envelope here at this stage.

# rule:[Forward]
if false # true
{
     redirect :copy "shit at gmail.com";
}

> remapping the address through postfix would be the better approach.

No, because postfix needs to know, and you create complicated relationships between outgoing mail servers and your mail server.
It would not surprise me if your solution is also using much more resources, because your solution constantly has to verify. Less cpu cycles is better for the environment. ;)

> this would mark the email as coming from the local sending server and
> the spf record sent down the line would reflect that.
> 
> spf verification would have already been verified by incoming postfix so
> you are not passing along something that got rejected in the first
> place?

No, not really relevant.

> 
> https://docs.microsoft.com/en-us/microsoft-365/security/office-365-
> security/high-risk-delivery-pool-for-outbound-messages?view=o365-
> worldwide
> 
> the above link was microsoft's explanation on why they refused to fix
> their spf record.
>

I see a manual about "Outbound delivery pools" no explanaition of why spf should not have '-all'

> 
> Apparently google is now also using unverified (or insecure) servers
> setup the same way.
>
> why i have no idea?

The only reason for using ~all, is because they do not know what servers are sending outgoing email. Afaik this is just a statement of being incompetent. Google does not give a fuck if others need to clean up their mess.
 
> Microsoft replied with the ticket after 3 months of messing around that
> they would not fix their spf record.
> 

Microsoft and Google are probably the companies you do 'business' with that have broken more laws than anyone else you know. Recently I have seen that Bill Gates is proud of his slogan "Why you should hire lazy people". Which undoubtedly is the cause of much of the shit I have with windows/exchange/outlook.
So forgive me if I do not really take Microsoft or Google as an example nor standard.