We'll need more details to understand what you are asking.  Please be as specific as possible.

when a user is logged on elgg some time without any action it is automatically disconnected from the site, how do I set up this time?

http://docs.elgg.org/wiki/Session_length

As Daniel says, use the Elgg api. You can't just insert into one table and expect that to work.

does anyone know if there is any plugin that does that?

There is a plugin called Upload Users (http://community.elgg.org/pg/plugins/naakka/read/384770/upload-users). Unfortunately, I haven't had time to test that on Elgg 1.7 or upgrade it for some time. But we used it succesfully in Elgg 1.5.

anyone can help me?

use é it should work.

I don't thing it's a good idea to change the app's encoding. Instead you should check if your .pt files are in fact in UTF-8. You can check it by using a text editor like notepad++ (windows).

Hello tiago

I have same problem too , email not sent to yahoo and Gmail new members !!!

How is this an Elgg problem? If some, but not all emails are delivered, it sounds like your server is having spam filter issues?

Kevin is right not an Elgg issue, it is likely an issue of reverse DNS on your server. Do you have this configured? Reverse DNS is when your IP points back at the domain, so my IP reverses to mail.mydomain.com. Your server needs to have a static IP address and support reverse DNS, many providers will block the email if it comes from an IP without proper reverse DNS.

Hope this helps!