[Mailman-Users] 461 Too many unknown users from your host

Mark Sapiro msapiro at value.net
Mon Jan 9 17:46:44 CET 2006

Munzir Taha wrote:

>My mailing list sends me lots of "Bounce action notification" messages. Each 
>messge has lots of emails that have permanent fatal errors
>First, why one notification cotains lots of emails? Do mailman group many 
>bounces in one message or what? Any doc to explain this?

Mailman doesn't group bounces, but it does group outgoing mail that
isn't VERPed or personalized. Thus, Mailman is sending one message to
many recipients in the same domain. The receiving MTA may thus reply
with one bounce message for all the undeliverable addressees in that
domain. Also, Your outgoing MTA may by sending a single DSN covering
all the undeliverable addresses in finds in one message.

>Second, one of the errors I got is:
>>>> DATA
><<< 461 Too many unknown users from your host. Possibly an open relay. Address 
>added to blacklist. If you think this is not correct please contact 
>blocked at gawab.biz and don't forget to include your network address and time 
>of seeing this message (#4.3.1)
><someone at gawab.com>... Deferred: 461 Too many unknown users from your host. 
>Possibly an open relay. Address added to blacklist. If you think this is not 
>correct please contact blocked at gawab.biz and don't forget to include your 
>network address and time of seeing this message (#4.3.1)
>451 4.4.1 reply: read error from mx2.gawab.com.
>I tested my server very well and it's not an open relay so is this still a 
>problem I can fix?

You have two problems. First, you have a number of bad addresses in the
gawab.com domain on your list and you have to stop trying to send to
them. Either unsubscribe them or disable delivery to them - also,
maybe set bounce processing so it is more agressive about disabling
bouncing users.

Second, because of your sending to unknown users at gawab.com, that
domain is now blocking all mail from you. You need to contact them
about removing the block.

>As far as I understand no user would get subscribed if he 
>has no valid email. Which means all those unknown users are used to be known 
>at one point of time until something happened. So, what?

If subscription to your list requires confirmation, then a user at an
address must be capable of receiving mail at that address in order to
subscribe in the first place, but such an address can later become
invalid. Also, there is no check on admin Mass Subscriptions. You can
subscribe any syntactically valid address via mass subscribe without
any check that it is actually deliverable.

Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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