Mark Sapiro writes:
On 6/12/26 3:03 PM, Paul Tomblin via Mailman-users wrote:
Can i append or pre-pend another transport file in the transport_maps listing and put in the entry for this domain that's been bouncing people off my list because of too many simultaneous connections?
I don't know what the transport for this domain would be, but the transport_maps setting can contain any number of lookup tables. See <https://www.postfix.org/postconf.5.html#transport_maps>.
Not sure exactly what you want; check the doc Mark recommends for syntax. This will refuse mail with some sort of 5xx (permfail) status to be relayed to example.com (and I think the "." means "and subdomains too").
transport.orig:# The error mailer can be used to bounce mail: transport.orig:# .example.com error:mail for *.example.com is not deliverable
But I think you probably want a "client-based" (host or IP) or "sender-based" (MAIL FROM) version, or perhaps a connection count throttle if you might ever want to receive mail from them. See
smtpd_client_restrictions (most flexible) sender_dependent_default_transport_maps smtpd_client_connection_rate_limit postscreen_client_connection_count_limit
Steve
-- GNU Mailman consultant (installation, migration, customization) Sirius Open Source https://www.siriusopensource.com/ Software systems consulting in Europe, North America, and Japan