Hello

I'd like to know what kind of solutions are large websites using for
lists management.

My guess is that they are sending the emails from their own servers
instead of outsourcing it to companies like aweber.com or
proautorresponder.com (which are ok but have several limitations).

If they are using their own servers, then which software are they
using? and how do they make sure that their emails are not being
filtered by anti-spam software?

If they are not using their own servers, then what's the name of the
companies they choose to outsourtce this task?

Thank you,

Manuel.

I think a lot of large companies are sending the email themselves,
because its important to send email on clean IP addresses (one free of
spam complaints).

There are a few SMTP servers out there that are designed for sending
large amounts of email.

XMS - http://www.activsoftware.com/xms/
StrongMail - http://www.strongmailsystems.com/
IronPort - http://www.ironport.com/
Lyris - http://www.lyris.com/

Some of the things you will want to make sure your doing to avoid the spam filters:
 - Setup a SPF record on your DNS server http://spf.pobox.com/ this is
a dns record that says which IP's can send email for your domain.
 - Sign your Email with DomainKey's - this will help on some ISP's
such as Yahoo. Soon you will also want to sign with DKIM, but no one
is using that yet.
 - Avoid words found in spam emails
 - Avoid sending mail to major isp's too fast, make sure your mail
server has some sort of throttling, or connection ramping.

One way to make sure your not ending up in the spam buckets is by
using a list seeding service. They basically provide you with a list
of email addresses on all the major isp's. Then when you send out your
email they give you a report telling you if it was filtered by
particular isp's. One company that offers this service is
http://pivotalveracity.com/