Re: sender rewrining advice

On 3/20/24 09:38, none wrote:

both on MX. LDAP routing when an email destined for host B, should temporary go to host A.

I assume by "should temporary go to host A" to mean while the message is relayed through host A?  As in host A is the MX the world sends to and host A then relays it to host B?  --  Or have I completely lost track?

correct

Okay.

LOCAL

Okay.
Does MX (host A?) have @example.com in it's relay-domains file (or somehow otherwise in class R)?

Ok so for this setup I should create Ldap routing entries like this.

I'm going to have to refresh myself on LDAP routing as it's been a LONG time.

mailLocalAddress: test@me.com / test@example.com
mailHost: (OUTGOING server)
mailRoutingAddress: test@guerrillamail.com

If I'm correctly picking up what you're putting down you are trying to say that mail to test@example.com should be forwarded to test@guerrillamail.com and go out via the OUTGOING server?
I believe you also said that you wanted MX to send the message to OUTGOING directly and not send it to LOCAL which would then send it back to MX on it's way to OUTGOING.
In this case MX is going to need some knowledge of how to do the routing for a non-local domain.
I'm going to have to dig out the Bat book and re-read about LDAP routing.
---
I'm confident that MX could relay @example.com to LOCAL and where LOCAL could forward the message to @guerrillamail.com and send it back out.
Aside:  LOCAL could send the email via MX which would send it on to OUTGOING or perhaps LOCAL could send it directly to OUTGOING.

but I have to allow relaying on OUTGOING with something like this in the access map
 Connect:(MX server)    RELAY

I think that you can add MX's hostname or IP address to the /etc/mail/relay-domains file.
N.B. you might should put the hostname in square brackets so that Sendmail doesn't do an Mail eXchanger lookup on MX's hostname. (Expanding action to differentiate from a colliding host reference.)

Is it wise to maybe reduce this to only the me.com/example.com or is there something different.

I don't know.

Would this be possible/better
 FEATURE(`blacklist_recipients')
 @me.com            RELAY
@example.com        RELAY

I'm not convinced that you need, much less what that.  At least not yet.

Is this what you had in mind?

No.
When I made the statement "you can have MX think that @example.com is local to it" I was thinking that MX would think that it's responsible for @example.com email addresses and that LDAP routing would be used to route some messages to LOCAL and other messages elsewhere, possibly forwarding them to guerrillamail.com.

Can you specify ip ranges there or host domains, so you do not do envelope rewriting when it is not necessary?

The method that I'm using -- I need to log in and copy some files to provide examples -- simply applies sender rewriting to any envelope that is not from a domain that Sendmail is responsible for; /etc/mail/local-host-names (class w).
I don't know how that would expand out with LDAP routing.
I do think that the config is relatively simple to change to have it read a different class that isn't used for anything else so that you could have it be something like dont-srs-domains type thing.

Do these sendmail rules get MX hosts for test@guerrillamail.com compare them with some configured/identified local network and everything not in the local network is rewritten?

No.
They look at the sending envelope address and compare it to the /etc/mail/local-host-names (class w).

I know, I thought referring to their function would be more clear.

Sometimes yes and sometimes no.

Yes indeed not nice, I have asked them to change it to ime.com. That fits better with the rest of their stuff.

LOL
--
Grant. . . .