Guys,
I've been getting this error at random times in my logs:
postfix/smtpd[18769]: warning: milter unix:/run/milter-greylist/milter-greylist.sock: can't read SMFIC_MAIL reply packet header: Broken pipe
Because of that, postfix drops the connection on the floor, and the sender gets a "Service unavailable error".
I don't see any other error messages around the same time that would give me any indication about what is going on. I am leaning around a possible racing condition with the milter-greylist software itself, maybe it's unable to cope with the amount of connections and the size of the database, but I am not sure, and I don't know how to debug the issue without enabling debug mode (which would fill out my logs with way more information than I can process).
This is affecting less than 1% of the incoming connections, but some times it happens with important senders, which make my customers pretty upset.
Anybody got any ideas?
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