On Mon, Jan 08, 2007 at 01:21:07AM -0500, Support Infocomplexe wrote: > > I came to ask myself what is the effect of the > dspam-spam_destination_recipient_limit = 1 > option exactly in all situation.
The _destination_recipient_limit sets the maximum number of recipients for the given destination; in this case the "dspam-spam" destination (which is itself defined in master.cf). It controls the maximum number of recipients the command will be invoked with at a time. For example, consider a message that is sent to five users at your domain. If the recipient limit is 1, then this will result in Postfix executing the delivery command five times - one invocation for each address. If it is set to 2, then it will execute it 3 times; the first two with two recipient addresses, and the last time with a single address. > I received a complaint about lost email and I though this option > was blocking email when multiple recipients are define in an > email. This is very unlikely, especially if it's set to 1. There's basically two reasons for it: 1. Efficiency. It's usually better to deliver multiple messages in as few goes as possible. If this is set to 1, then that example email with 5 recipients will result in five separate messages being created. 2. Reliability. Some processing commands may not support multiple recipients, or may not handle error conditions very well when processing mail for multiple recipients. For example, if the destination is invoking a command and it returns a failure code, Postfix doesn't have any way of knowing which of the recipient addresses failed; therefore, it will requeue the message and attempt delivery to _all_ recipients again at a later stage. If the command sent mail to the first few but then encountered an error, they'll receive duplicates of that message. > I tried the value 100 and I had no problem. I saw that postfix > sent message as a single shot in my log when set to 100 but sent > one by one when set to 1. I need to figure out to what value to > set this option to make sure I dont lose emails. This option should not have any influence over "missing" emails; and it's more likely that having multiple recipients (i.e. a value greater than one) would exhibit problems. If your dspam-spam destination is using LTMP to deliver messages to the daemon, then you might improve performance by having this set to deliver to multiple recipients simultaneously. It's likely to be insignificant in most cases as dspam has to re-process each message for each user anyway. I don't know whether it optimises the case where each recipient is a member of the same group and thus has the same tokens.
