Hi, when I try to send an e-mail to my list (only one recipient, the list itself), I get these:

Aren't you creating a loop here? Why are you putting the list itself on the list as its only recipient? This appears to me to be an invitation for an endless loop.

-- Lindsay Haisley | "Real programmers use butterflies" FMP Computer Services | 512-259-1190 | - xkcd http://www.fmp.com |

Rodrigo Abrantes Antunes writes:

Searching google I found that this error isn't related to the number of users in the list, it occurs because the total number of addresses in the To: and Cc: headers of the post equals or exceeds max_num_recipients.

The operational issues have already been addressed well in other posts. However the above statement is incorrect, and needs clarification.

The items visible in your personal mail client (MUA) in the To:, Cc:, and Bcc: fields are usually called "addresses" or "addressees". These are different from "recipients", which are the addresses that the host-to-host mail program (MTA) sends to. Mailman "explodes" the list's *address* into a large number of *recipients*, and asks the MTA to deliver to that whole list of recipients, or to chunks of it as Mark explains elsewhere. You will in general never see the list of recipients of a post unless you look at the MTA's logs.

By the way, there's nothing wrong with your understanding of plain English, in which "address" and "recipient" are pretty much the same. However, in technical discussion these words are often distinguished as above.

But in documentation is said that if this option is set to 0 it has no limit.

The limit you are running into here is not in Mailman, it is in the MTA. Mailman cannot tell the MTA what to do; it can only restrict itself to a small enough number that the MTA will cooperate with it.

Citando Lindsay Haisley <fmouse-mailman@fmp.com>:

On Mon, 2012-10-22 at 13:46 -0200, Rodrigo Abrantes Antunes wrote:

...

Any ideas? The behavior of Mailman with respect to the number of recipients specified in any single SMTP transaction is controlled by SMTP_MAX_RCPTS, which should be less than the max number of recipients allowed by the SMTP server for any single transaction.  If your setting up this loop to stress-test your installation, set SMTP_MAX_RCPTS in mm_cfg.py to a small enough number to pass muster with the contas SMTP server.

-- Lindsay Haisley       |  "Humor will get you through times of no humor FMP Computer Services |      better than no humor will get you through 512-259-1190          |         times of humor." http://www.fmp.com    |            - Butch Hancock

---

Mailman-Users mailing list Mailman-Users@python.org http://mail.python.org/mailman/listinfo/mailman-users Mailman FAQ: http://wiki.list.org/x/AgA3 Security Policy: http://wiki.list.org/x/QIA9 Searchable Archives:
http://www.mail-archive.com/mailman-users%40python.org/Unsubscribe:
http://mail.python.org/mailman/options/mailman-users/rodrigoantunes%40pelota...

I didn't set any loop, the list's e-mail obviously isn't a list member, what I said is that when you want to send and email to the list you put the list's email in the "To:" field and that's the only recipient when I'm sending e-mail, I'm not putting more recipients in "to:" field wich could burst the limit of max_num_recipients if this limit was set.

I've set SMTP_MAX_RCPTS to 250 in mailman and smtpd_recipient_limit to 300 in postfix and I'm still getting these errors.

On Tue, 2012-10-23 at 13:45 -0700, Mark Sapiro wrote:

On 10/23/2012 1:21 PM, Rodrigo Abrantes Antunes wrote:

...

I've set SMTP_MAX_RCPTS to 250 in mailman and smtpd_recipient_limit to 300 in postfix and I'm still getting these errors.

Did you restart Mailman

IMHO, a restart of postfix would probably be in order, too. I know that many settings in my mail server, courier MTA, require a restart of the server after changing them in order for them to take effect.

Mark, Brad, etc. I have a question here. Rodrigo says that in his Mailman smtp log, a SMTP transaction to contas for 828 recipients was "completed in 1.705 seconds"

Mailman also reports a _temporary_ failure of 450 addresses. Because this is a 4xx class error, can one assume that after accepting smtpd_recipient_limit "rcpt to" addresses, postfix started rejecting each new address with a 452 (4.5.3) error, and that Mailman continued to attempt to send recipients in spite of this? - after which Mailman sent, and postfix accepted, the body of the message?

This is the only scenario that makes any sense in light of the reported temporary failure. Is Mailman smart enough to pick up the thread on this and re-send to those addresses which were refused?

The only other possible scenario is that the SMTP server bounced the entire message after transmission of the message body was complete, based on an excessive number of recipients. In this case, wouldn't it make more sense for the mail server to return a 5xx (permanent) class error?

Inquiring minds want to know. I don't know postfix, and because all my outgoing lists have VERP personalization enabled, this problem never comes up here.

-- Lindsay Haisley | "We have met the enemy and he is us." FMP Computer Services | 512-259-1190 | -- Pogo http://www.fmp.com |

Lindsay Haisley wrote:

Mark, Brad, etc. I have a question here. Rodrigo says that in his Mailman smtp log, a SMTP transaction to contas for 828 recipients was "completed in 1.705 seconds"

Mailman also reports a _temporary_ failure of 450 addresses. Because this is a 4xx class error, can one assume that after accepting smtpd_recipient_limit "rcpt to" addresses, postfix started rejecting each new address with a 452 (4.5.3) error, and that Mailman continued to attempt to send recipients in spite of this? - after which Mailman sent, and postfix accepted, the body of the message?

First of all, it is not clear how many recipients were sent in this SMTP transaction.

The 828 recipients was the entire list, but the list is chunked into pieces of *at most* SMTP_MAX_RCPTS (default 500) and each chunk is sent as a separate SMTP transaction. Further, the chunks ar separated by top level domain such that all .com addresses are in their (set of) chunks; all .net and .org addresses are in a separate set; all .edu, .us and .ca addresses, and the rest are in yet another set.

That notwithstanding, the actual SMTP transaction is handled by Python's smtplib module. The fact that there were no smtp-failure log messages that indicate an exception from smtplib (these would be log messages like 'All recipients refused: %s, msgid: %s', 'SMTP session failure: %s, %s, msgid: %s' or 'Low level smtp error: %s, msgid: %s') indicates that smtplib detected that at least one recipient was accepted and returned a dictionary, with one entry for each recipient that was refused. Each entry contains a tuple of the SMTP error code and the accompanying error message sent by the server. These are reported as indicated in the OP.

Mailman then records any permanent failures as bounces and if there are temporary failures as here, updates the recipient list for the message to contain only the temp failed addresses and queues it in the retry queue to be retried.

Thus, if the MTA is accepting say 50 recipients out of 500, the 500 will eventually all be delivered after about 10 times the retry interval which defaults to 15 minutes.

This is the only scenario that makes any sense in light of the reported temporary failure. Is Mailman smart enough to pick up the thread on this and re-send to those addresses which were refused?

See above.

The only other possible scenario is that the SMTP server bounced the entire message after transmission of the message body was complete, based on an excessive number of recipients. In this case, wouldn't it make more sense for the mail server to return a 5xx (permanent) class error?

That didn't happen here. If it had, the smtplib process would have thrown a smtplib.SMTPResponseException and this would have been logged with a 'SMTP session failure: %s, %s, msgid: %s' message.

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

On Tue, 2012-10-23 at 18:21 -0200, Rodrigo Abrantes Antunes wrote:

I didn't set any loop, the list's e-mail obviously isn't a list member, what I said is that when you want to send and email to the list you put the list's email in the "To:" field and that's the only recipient when I'm sending e-mail, I'm not putting more recipients in "to:" field wich could burst the limit of max_num_recipients if this limit was set.

OK, I'm sorry. I misunderstood.

I've set SMTP_MAX_RCPTS to 250 in mailman and smtpd_recipient_limit to 300 in postfix and I'm still getting these errors.

Did you restart Mailman and postfix? What do the Mailman log files show with regard to the number of recipients (smtp log) and the number of failures (post log) _after_ your changes and a restart of both postfix and Mailman? What's the total number of subscribers on the list (i.e. how many "rcpt to" addresses did Mailman _attempt_ to submit for posting)?

Do your mail system logs shed any light on anything? My mail logs are always my first stop when trying to debug a mail problem.

-- Lindsay Haisley | "Fighting against human creativity is like FMP Computer Services | trying to eradicate dandelions" 512-259-1190 | http://www.fmp.com | -- Pamela Jones