Thank you Wietse & Viktor for the response. Much appreciated.
Regards Tom On Mon, Apr 18, 2016 at 5:52 PM, Viktor Dukhovni <postfix-us...@dukhovni.org > wrote: > On Mon, Apr 18, 2016 at 12:15:13PM +0200, Thomas kinghorn wrote: > > > In master.cf > > > > transport_maps = hash:/etc/postfix/vox_transport > > vox_destination_concurrency_limit = 20 > > vox_destination_rate_delay = 2s > > Setting a rate delay reduces the concurrency to 1. > > > vox_destination_recipient_limit = 6 > > Setting a low recipient limit causes multi-recipient mesages to > split into more parts and consume more connections. > > So if the destination accepts more than 6 recipients at a time, > use a larger limit. > > The best way to resolve your issue is to get whitelisted by the > receiving system. > > You may be able to reduce the impact of downstream connection limits > by slowing down positive and negative feedback: > > smtp_destination_initial_concurrency = 2 > smtp_destination_concurrency_positive_feedback = 0.2 / concurrency > smtp_destination_concurrency_negative_feedback = 0.5 / concurrency > > This will grow the concurrency for each destination more slowly > and and will avoid throttling too quickly. > > -- > Viktor. >
