Sorry about that. The site isn't mine, I'm just helping out the webmaster. {Edit} I decided to PM the site to you at this time incase robots collect the info.
We deleted the member and also that deleted the posts but I need to delete all the PMs he sent.
Alright. I received the message. Just so you know, I would strongly suggest re-doing that entire site. It is absolutely shitty.
Anyway, the SQL command you need to run is this:
delete from `smf_personal_messages` where `ID_MEMBER_FROM`=xx
Where "xx" is the member ID number assigned when they signed up. For example: You are user ID# 802 on this particular forum so in phpMyAdmin you'd query this:
delete from `smf_personal_messages` where `ID_MEMBER_FROM`=802
Also, if you're ever curious how many a particular member did actually send, then you can run this SQL query prior:
SELECT count( * )
FROM `smf_personal_messages`
WHERE `ID_MEMBER_FROM` =xx
Now I'm assuming your database is using the prefix "smf_". If not, then you'll need to change that variable.