Hello,
 
Thanks to your advices, i manage to put a throttle by domain by adding
 
in my master.cf
 
domain1      unix  -       -       n       -       -       smtp
        -o smtp_fallback_relay=

in my transport :
 
domain1.tld    domain1:

and in my main
 
domain1_destination_rate_delay = 60s

but i would like to know if there is a way to send for 10 mails with destination rate delay to domain1 equal to 0 then to throttle (so for instance wait 1 min) then 10 mail then wait etc,
 
Thank you for your help :)

Hello,
 
I use Postfix as a relay SMTP to send bulk mail (newsletter).
 
And I would like to regulate them according to the domain name of the recipient.
 
For example, if I have to send 100 emails to domainA and 100 mails to domainB
 
I would like Postfix regulate those mails by sending in a first time 50 emails to domainA and 50 emails to domainB then in a second time 50 mails to domainA and 50 emails to
 
domainB.
 
Is there a solution to my problem?
 
Thank you for your answers.