I've got a PHP script that sends newsletters to a bunch of email adresses, it sends 15000 newsletters an hour, until all email adresses have been processed.Because this process isn't run in one time, I have a table where I register all the adresses which have been mailed, so I can always easily get the unmailed adresses.Here is a simplified example of what I do:\[code\] select a.* from email_all a left outer join email_send s on s.email_id = a.id and s.mailing_id = 1 where s.id IS null limit 0, 15000\[/code\]So all the adresses who haven't been mailed yet are selected, now the problem is, the more newsletters have been sent, the more adresses that are logged in the 'email_send' table and the slower the query gets. In the beginning there are 50.000 adresses in the table 'email_all', and in 'email_send' there are none, after a few ours there still are 50.000 adresses in table 'email_all', and also 50.000 adresses in 'email_send', and then all hell breaks lose. The scripts works perfectly for smaller mailings, like 10.000.I've placed an index on the column 'email_id' in the second table, primary keys have been set.Is there anyway I can speed it up? I've used 'NOT EXISTS IN' too but that doesn't help 
Anyone can help?Thx!!Steve
Anyone can help?Thx!!Steve