The full error is likely to be something like this example:
'A timeout occurred while communicating with server.
Account pop3.xxxx.yy.zz, SMTP server: 'smtp.xxxx.yy.zz', Error Number: 0x800cc19'

Resolutions that we are aware of:

It can be caused by the configuration of Spamkiller software (Mcafee).
Please turn Spamkiller off and try again.