f



Force sendmail to connect to itself....

Hi Folks,

Is there a way to do this ? Long story short we use sendmail to deliver all=
 messages to a third party product which adds a header and resubmits the me=
ssage back to sendmail which then routes the message based on that header. =
This has worked fine until now because the third part product dropped the i=
nitial 250 banner response line thus sendmail was not aware it was connecti=
ng to itself. However this was a bug in earlier versions of the third party=
 application which is now fixed, thus when mail delivery is attempted the f=
ollowing error is observed....

SYSERR(root): prevent config error: mail loops back to me (MX problem?)

I understand the concept behind this safety mechanism but it really is a pa=
in when you have added appropriate configuration to route the messages appr=
opriately based on the added custom header.

Note the third part app acts as a transparent proxy which is why it (correc=
tly) thinks it is connecting back to itself.

Can this check anti mail loop check be disabled in any way ?

Best regards, Peter.
0
peter
9/26/2016 4:48:27 PM
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peter.mccracken@gmail.com wrote:
> Is there a way to do this ? Long story short we use sendmail to
> deliver all messages to a third party product which adds a header and
> resubmits the message back to sendmail which then routes the message
> based on that header. This has worked fine until now because the third
> part product dropped the initial 250 banner response line thus
> sendmail was not aware it was connecting to itself. However this was a
> bug in earlier versions of the third party application which is now
> fixed, thus when mail delivery is attempted the following error is
> observed....
>
> SYSERR(root): prevent config error: mail loops back to me (MX problem?)
>
> I understand the concept behind this safety mechanism but it really is
> a pain when you have added appropriate configuration to route the
> messages appropriately based on the added custom header.
>
> Note the third part app acts as a transparent proxy which is why it
> (correctly) thinks it is connecting back to itself.
>
> Can this check anti mail loop check be disabled in any way ?

Add F=k flag to the relevant mailer to disable the check.
(Sendmail-8.7 and above)

e.g. to modify "relay" mailer in sendmail.mc use the following line:

MODIFY_MAILER_FLAGS(`RELAY', `+k')dnl

BTW The flag is used in submit.cf to disable such checks (see feature/msp.m4).

-- 
[Andrew] Andrzej A. Filip  -  https://www.linkedin.com/in/andfil
0
Andrzej
9/26/2016 5:15:00 PM
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