Too many messages sent blocked Postfix
 

Hello,

I have Postfix/Cyrus configuration installed and yesterday I tried to send 500 emails withing 1 min. It seems Postfix blocked and I can't send emails with it. After I run mailq command I saw 475 messages in queue. After 10 ours there are only 417. Can I rush this process? Is there a way to prevent this thing from happening in the future?

Try postqueue -f to flush the queue, but you really need to work out what is causing the delay - is it a DNS issue, etc., etc.

What do you logs say?

Thank you for reply. Which logs should I check? There are too many for my knowledge. :) Maybe I did send too many emails too fast.

depends on your distro, but something like /var/log/maillog

Hello,

I read about my problem on the internet. It seems it's a bug in Postfix. Let's say I want to send 100 emails, with 1 sec pause after each one. The first one is sent and all the other go to mail queue with status/error "delivery temporarily suspended: unknown mail transport error". In 2-3 days all emails are sent, but this is not a good behavior.

Do you think is possible to upgrade Postfix (using yum) without loosing the existing configuration files? I am afraid to update, maybe I will have to reconfigure everything again.

What version are you using. Depending on the version you move from, the config file may work or may need updating. There an update utility, but I can't recall the name.

You could either simply save your current configuration and replace it after the upgrade (depends how you upgrade), but a better way would be to simply look at the output of

postconf -n

which will tell you what you've changed from default. Note that this won't show changes to master.cf

I think my Postfix version is 2.2.10. Do you think I can upgrade it keeping the config?

I can't see when 2.2.10 came out, but I would think the config should work with and update.

make sure you keep a copy of postconf -n in case you need to create a new one