I'm trying to get my mail on my macbook up and running but am encountering problems. When trying to send mail I'm asked for my account password for 'smtp.mail.com:username". My password is rejected, even though I've changed the password in mail/preferences/accounts, and also tried changing the smtp port from 25 to 587 as advised on another forum, still nothing works. Is there a password from my internet provider I'm missing or something? HELP