If you have a new magento installation, and you notice that the join process takes a very long time to complete, your sendmail is probably the source.
Some new servers dont have sendmail setup properly and you need to adjust a few things.
For slow email from the app, edit 3 files.
1) /etc/resolv.conf, add search whateveryourdomainnameis.com in before the nameservers.
[root@Web1 etc]# cat /etc/resolv.conf
2) /etc/mail/sendmail.cf Uncomment the line 0 HostsFile=/etc/hosts
# hosts file (normally /etc/hosts)
3) /etc/hosts add www.whateveryourdomainnameis.com and whateveryourdomainnameis.com to the IP address for this server.
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
127.0.0.1 www.whateveryourdomainnameis.com whateveryourdomainnameis.com
4) Also I added sendmail to the chkconfig to make sure it restarts if the server restarts
[root@Web1 etc]# chkconfig sendmail on