The mailing list for listmasters using Sympa

[Ruud Baart <address@concealed>]

Thank you. I implemented this idea.

While I was doing that I thought of a more general solution. Because 
today it's wanadoo and orange. Tomorrow it might be others. Generally 
speaking, sending a lot of mail at once is suspicious. If the "burst" 
per list can be controlled it might be a help. I haven't tried it yet 
but wouldn't something like this be more generally useful?

In the list definition, a header is added. For example something like:
X-SMTP-rule: veryslow

In postfix, in main.cf is added:
    smtp_header_checks = regexp:/etc/postfix/smtp_header_checks

and then in /etc/postfix/smtp_header_checks:
    /^X-SMTP-rule: (.*)$/ FILTER veryslow:$1

In master.cf it is
    veryslow unix - - n - 10 smtp -o initial_destination_concurrency = 
2,destination_concurrency_limit = 2.....

What do you think of this idea?


Op 5-7-2022 om 23:31 schreef Matt Taggart:
> On 7/5/22 14:05, Ruud Baart wrote:
> > Hi,
> >
> > My Sympa installation (6.2.68) works ok with postfix on my Debian 
> > server but it is too fast. I get errors like:
> >
> >     Jul  5 17:47:52 mail postfix/smtp[2888446]: 4D48D81019:
> >     to=<address@concealed>, relay=smtp-in.orange.fr[80.12.26.32]:25,
> >     delay=3.4, delays=0.13/0.09/3.1/0, dsn=4.0.0, status=deferred (host
> >     smtp-in.orange.fr[80.12.26.32] refused to talk to me: 421
> >     opmta1mti29nd1 smtp.orange.fr 8kmDofKH1S6M1 Trop de connexions,
> >     veuillez verifier votre configuration. Too many connections, slow
> >     down. OFR004_104 [104])
>
> We have problems with orange.fr/wanadoo.fr too. So much so that we 
> created a separate postfix transport for it.
>
> setup an orange_transport transport map:
> orange.fr    orange:
> .orange.fr    orange:
> wanadoo.fr    orange:
> .wanadoo.fr    orange:
>
> create an orange transport in master.cf with 10 dedicated processes:
> orange    unix  -       -       n       -       10      smtp
>
>
> main.cf:
> add orange_transport to transport_maps plus this
>
> ## orange
> # they want us to limit to 3 but they have two MXs
> # these limits are enforce per DOMAIN (not per transport)
> orange_initial_destination_concurrency = 2
> orange_destination_concurrency_limit = 2
> orange_destination_recipient_limit = 50
> orange_destination_rate_delay = 3s
> # with a delay set we need to set failed cohort limit to prevent 
> deferred mail
> #  after a single error
> orange_destination_concurrency_failed_cohort_limit = 50
>
> This only helps some,  delivery is still often slow/bouncy.
>
> This shows the hazard of trying to block spam by rate limiting inbound 
> smtp connections, you end up blocking legit mail from mailing list 
> servers.
>
> Microsoft is a whole other set of problems...