hello, What system specs would you recommend for someone trying to send around 4mil emails daily through smtp without having the messages sit in the queue and get backed up? (all emails are double opt-in and perfectly legal) thanks in advance
4 mill / d is quiet some traffic for smtp communication with receiving servers hence i would recommend a regular dedicated server. the disk space itself is uncritical but most dedicated servers come with drives 200+ GB anyway and most servers even cheaper ones in the price-range 50-70 US$ of have sufficient resources - usually dual core, 4 GB RAM, to handle your smtp traffic the exact resources depend on recipients some recipients use cheap mail accounts with slow servers, time ouits, server down, etc and thus with a need for multiple reconnections every 4 or so hours if you want ALL mail to be delivered or at least the typical default of max 4days retries every 4 hrs. it is those reconnections that consume resources / create traffic. hence you may want to limit your smtp to less than 4 days retries or to a single retry more than 4 hours later
I have a quad core amd processor with 8 gb ram, and I have installed ubuntu on the server, and the server only has exim4, and it is configured as a smarthost for the server that hosts the site. I am able to send around 6 mil mails in about 10 hours. This config should work for you I guess.
Hello, Hardware won't be very important meanwhile I would suggest you to use dual core processor machines. However the tunning of your MTA will be critical and should be designed by a mail expert. For that kind of configuration, I would recommand using Sendmail with multiple queues and instances enabled. Basically you need to split your configuration into two parts: the sending and the delivery. This is always the ways I am using building bulk mail systems. Regards Thibaut,Sendmail expert