Hello. I'm very new to Postfix configuration; I switched from Sendmail
because I want to send mail through the Amazon Simple Email Service and
Postfix has concurrency options that were easier to understand.
However, they're not doing what I want and the mail is going too slow.
Sending mail via Amazon happens via piping it to a program that makes an
HTTP connection. This takes about 0.5 seconds. We have a high volume
of mail that needs to be delivered at a rate of at least 10 messages per
second, and our Amazon account supports up to 90/s. But when I send
mail with sendmail.postfix it appears synchronous, i.e., takes 0.5 s to
return. Amazon says that concurrency is the way to increase the rate:
make multiple simultaneous connections.
I was hoping that Postfix would do this for me, i.e., that calling
sendmail.postfix would return instantly, queueing the message up and
executing as many parallel connections as it was configured for. It
doesn't; either I haven't configured it right or I'm wrong about how
sending works. I could of course background each call to
sendmail.postfix but then I'd have to do my own concurrency management
to throttle the number of simultaneous processes I had running that, and
that seems to me to be exactly what Postfix should be doing for me.
Part of my main.cf:
default_transport = aws-email
default_destination_concurrency_limit = 1000
aws-email_destination_concurrency_limit = 1000
default_process_limit = 1000
Part of my master.cf:
aws-email unix - n n - 0 pipe
flags=R user=mail argv=/path/to/ses-send-email.pl [...] -f ${sender}
${recipient}
I'm sending mail with:
/usr/lib/sendmail.postfix -t -f<fromaddress>
Is it possible to send mail with a faster return than 0.5 seconds and
have Postfix manage the sending queue for me with concurrency? What am
I missing, please?
