Question about excessive bounces
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Hi,
I administrate two Mailman mailing lists at ScienceByEmailHTML and ScienceByEmailPlain. We have approximately 39 000 addresses in the former list, and about 1000 in the latter. I have a question about the bounces we receive.
We have the lists set so after five bounces, the address is automatically disabled. An notification is sent alerting us to the disabled account, where we then delete the address from our own records as well as Mailman.
Depending on the week, we can get over a hundred of these notifications which come in batches, arriving typically on Friday (although we also get waves coming in on Monday as well).
However, we can also go a week without receiving a single one. Given the spread of excessive bounces is often in excess of a hundred, and rarely fewer than 60 or 70, I'm wondering if you know why this might be the case. Also, why do they arrive in waves? Is it collated and sent periodically through Mailman, or is it a result of batches of bounces being sent back from servers?
Cheers,
Mike
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- Mike.Mcrae@csiro.au <Mike.Mcrae@csiro.au>:
Well, since bounces are generated when mails are sent via the list, the waves would correspond to about ever 5th posting on the list.
No traffic -> No bounces -> no unsubscriptions
-- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebrandt@charite.de | http://www.charite.de
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<Mike.Mcrae@csiro.au> wrote:
I administrate two Mailman mailing lists at ScienceByEmailHTML and ScienceByEmailPlain. We have approximately 39 000 addresses in the former list, and about 1000 in the latter. I have a question about the bounces we receive.
We have the lists set so after five bounces, the address is automatically disabled. An notification is sent alerting us to the disabled account, where we then delete the address from our own records as well as Mailman.
Mailman will automatically delete members with delivery disabled by bounce according to the settings bounce_you_are_disabled_warnings and bounce_you_are_disabled_warnings_interval. If bounce_you_are_disabled_warnings is set to 0, the member will be removed immediately after the disabling bounce is received.
Depending on the week, we can get over a hundred of these notifications which come in batches, arriving typically on Friday (although we also get waves coming in on Monday as well).
This is strange. Unless you only post on Friday's and Mondays, or unless there is some unusual reason for the bouncing addresses to "go bad", I would expect bounces to be uniformly distributed over the days there are posts.
Also, I find it possibly unusual that even out of 40,000 addresses that 100+ per week "go bad", but maybe not.
However, we can also go a week without receiving a single one. Given the spread of excessive bounces is often in excess of a hundred, and rarely fewer than 60 or 70, I'm wondering if you know why this might be the case. Also, why do they arrive in waves? Is it collated and sent periodically through Mailman, or is it a result of batches of bounces being sent back from servers?
Mailman collects bounces and processes them in batches, but this depends on the Defaults.py/mm_cfg.py setting REGISTER_BOUNCES_EVERY which defaults to 15 minutes, and even if it were for some strange (and probably misguided) reason set to something like 5 to 7 days, I would still expect "bounce day" to be more variable.
You need to check Mailman's 'bounce' log to see when bounces are being received/registered, and Mailman's 'smtp-failure' log for potential delivery issues. You also need to look at the actual bounce notifications attached to the disabled notices to see that these seem to be legitimate bounces.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
Mark Sapiro wrote:
There is also the possibility that due to some strangeness in your outgoing MTA, messages are queued there for a long time and sent mostly on Fridays and Mondays. Look at your MTA's logs and perhaps Mailman's 'smtp' log too and see what's going on there.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/267565c6ab7816fe29beedf9a9cbcd44.jpg?s=120&d=mm&r=g)
- Mike.Mcrae@csiro.au <Mike.Mcrae@csiro.au>:
Well, since bounces are generated when mails are sent via the list, the waves would correspond to about ever 5th posting on the list.
No traffic -> No bounces -> no unsubscriptions
-- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebrandt@charite.de | http://www.charite.de
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
<Mike.Mcrae@csiro.au> wrote:
I administrate two Mailman mailing lists at ScienceByEmailHTML and ScienceByEmailPlain. We have approximately 39 000 addresses in the former list, and about 1000 in the latter. I have a question about the bounces we receive.
We have the lists set so after five bounces, the address is automatically disabled. An notification is sent alerting us to the disabled account, where we then delete the address from our own records as well as Mailman.
Mailman will automatically delete members with delivery disabled by bounce according to the settings bounce_you_are_disabled_warnings and bounce_you_are_disabled_warnings_interval. If bounce_you_are_disabled_warnings is set to 0, the member will be removed immediately after the disabling bounce is received.
Depending on the week, we can get over a hundred of these notifications which come in batches, arriving typically on Friday (although we also get waves coming in on Monday as well).
This is strange. Unless you only post on Friday's and Mondays, or unless there is some unusual reason for the bouncing addresses to "go bad", I would expect bounces to be uniformly distributed over the days there are posts.
Also, I find it possibly unusual that even out of 40,000 addresses that 100+ per week "go bad", but maybe not.
However, we can also go a week without receiving a single one. Given the spread of excessive bounces is often in excess of a hundred, and rarely fewer than 60 or 70, I'm wondering if you know why this might be the case. Also, why do they arrive in waves? Is it collated and sent periodically through Mailman, or is it a result of batches of bounces being sent back from servers?
Mailman collects bounces and processes them in batches, but this depends on the Defaults.py/mm_cfg.py setting REGISTER_BOUNCES_EVERY which defaults to 15 minutes, and even if it were for some strange (and probably misguided) reason set to something like 5 to 7 days, I would still expect "bounce day" to be more variable.
You need to check Mailman's 'bounce' log to see when bounces are being received/registered, and Mailman's 'smtp-failure' log for potential delivery issues. You also need to look at the actual bounce notifications attached to the disabled notices to see that these seem to be legitimate bounces.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
![](https://secure.gravatar.com/avatar/56f108518d7ee2544412cc80978e3182.jpg?s=120&d=mm&r=g)
Mark Sapiro wrote:
There is also the possibility that due to some strangeness in your outgoing MTA, messages are queued there for a long time and sent mostly on Fridays and Mondays. Look at your MTA's logs and perhaps Mailman's 'smtp' log too and see what's going on there.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
participants (3)
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Mark Sapiro
-
Mike.Mcrae@csiro.au
-
Ralf Hildebrandt