can't send email using different account

My client has 7 different accounts, and for some reason, the last 2 won’t let me SEND EMAIL AS those emails.


Please go to Tools>Accounts and make sure those two accounts have all their checkboxes (IMAP, SMTP, etc.) checked. 

Dear David: Theres many people having troubles with sending large emails (2mb & up) the emais stand on outgoing tray, and never pass to send tray. Can you help us?