> > A client asked me to build for him a mail solution, capable 
> of sending 
> > up to
> > 1 milllion emails a day, while each email doesn't exceed 
> 50KB in size.
> How many users will you have reading mail, or this outgoing 
> mail only -- for "marketing" purposes?

Outgoing only 

> Hardware-wise, Postfix can easily handle the sort of drops 
> you are talking about.
> Victor Duchovni, resident Postfix guru, once set up an 
> 11-machine backend to do a million messages per hour. You 
> could get away with fewer servers if you are willing to 
> extend your total drop time.

I am more familiar with sendmail, so would prefer it as a MTA.
If this is a problem, I'll have to learn Postfix, which is possible.

> Assuming no A/V and/or content filtering, most setups are I/O 
> you definitely want a proper disk subsystem.
> > 4) what is your recommended software solution
> Postfix, LDAP, Dovecot, with a NetApp backend.

Not MySQL but LDAP? Could you explain?

> > 3) is there any max emails a day from IP/domain, which 
> triggers black
> >    and blocklists
> That is the real problem. How big are your lists and where 
> did you get them from? A million emails a day sounds like you 
> would run into trouble very quickly.

Right, looks troublesome.
Is there an equation to know approximate maximum of emails/day per
The lists are 1-2 millions, legally bought.

> In addition to the admins you hire to manage this mail setup, 
> I would strongly recommend you have a dedicated team of 
> deliverability people.

I am sorry, I don't understand the meaning of deliverability people - could
you please explain this a bit further?

> Also, you should have multiple upstream ISPs, most ISPs 
> nowadays are fairly strict nowadays and a million message 
> drop/day sounds like you will be getting lots of 
> cease-and-desist notices from your ISPs.

Even if the servers are co-located and distributed among data centers and
have dedicated pipes each?

Thank you, Thomas!

> Thomas