SMTP authentication causing problems in email...

I've successfully set up my Gmail email account in my Nokia 9300
smartphone email client. I can send and retrieve emails. The problem is
that I get an error message after sending email, though it has
successfully been sent and received by the recipient.

After a lot of research in a Nokia 9300 community forums, I've been
told that the problem lies in SMTP authentication. I need to check
email first before I send any, for checking email activates the SMTP
authentication.

Is there a way I can bypass this? Sometimes I need to just send fast
emails on the move without checking mail.

I appreciate your help,
Thanks