Cannot send mail with attachment through SMTP server

[RSeven]

In my windows mail account, i have set up my personal POP account of gmail. But after this, i am unable to send mail containing attachment. Earlier i could send mail with or without attachment. Now while sending attachment emails, i get some 'error 554' and some '0x800cccf6' code along with it. I guess this problem is due to some SMTP server issue because i have same settings on the outlook express on an another machine it doesn't give any such problem. So what must be the problem?

[Ashok.M]

Is the machine you are facing problem with windows mail a laptop?
If you give the error message as it is then that will help much to understand the cause.

[techman]

I know gmail has published the settings for IMAP accounts. I am not sure if the POP accounts are also supported. I will check it out.