k9 or gmail

And by the way i am using pop3 account that's linked
to my home cabel internet email client!
 
What do you mean by faster? Faster to open/close the app, faster to open an email, faster to receive sent emails, etc.?

It's hard to say which uses less battery. Yes, different apps can use a different amount of battery, but for email apps, a big factor is how the accounts are set up, and what type of accounts they are.

If you have a POP account set up to check email every 5 minutes, that's generally going to consume more battery that an IMAP account. However, if you set it to only check every 1-2 hours, it's most likely going to consume less battery than an IMAP account.

My primary account is my Gmail, and the Gmail app works fine for my purposes. I tried K9, but it wouldn't work with my Yahoo account over IMAP. I'm currently using MailDroid for my other email addresses, partially because it works with my Yahoo account over IMAP, and also because I liked it better than K9. I can be a little bit laggy at times (opening the app itself), but not enough that it really bothers me. I've changed it to cache emails as they come in, and email open almost immediately. I have 4-5 accounts set-up via IMAP, 3 via POP, and MailDroid uses very little battery/CPU.
 
Faster to receive mail or with pop3 do they all have to go fetch the mail at what interval you set!
 
IMAP is push email, so there is no check interval. So, when the email hits your inbox on the server, it should get 'pushed' to your device. POP is pull, where the client typically checks on a timed (or manual) interval. If you want to receive emails on your device as soon as possible after it hits your inbox on the server, you want to use an account that supports IMAP. Gmail is IMAP.
 
So if my web mail is pop3 and I use Gmail I should get the mail alot quicker than k9 and save battery I have k9 set to fetch every 15 min but if I have it fetch more often then it will be more strain on my battery right? Which one do u think?
 
So I set Gmail back up I just made my pop3 account forward to Gmail and now it is instant but why can I not delete the trash folder there is no option!
 
So I set Gmail back up I just made my pop3 account forward to Gmail and now it is instant but why can I not delete the trash folder there is no option!

In the Gmail app, hit your menu button, and then 'Go to labels'. Your Trash folder should show up in there. Is that what you're looking for?
 
Yah thanks I knew that if I delete the inbox it goes to trash but u can not delete the trash off the phone unless u long in to your Gmail account online and do it from there its a limitations of Gmail but thanks for the help!