Myself and 4 work colleagues are experiencing the same problems with email on Outlook Express. We can only send 'new' mail as any mail sent using 'reply' , 'Forward' etc does not send. For example, if you send an email to John Smith using 'reply' or 'forward' it does not work, but if you send it to John Smith using 'create new mail' it works fine.
I also presume that these emails you cannot reply to are replies from emails originally sent by you? You need to go to the 'from' line and change it to your current email address before sending it. I think you may have changed isp or emails recently? In the 'from' line it will show your original email address and you must click the arrow at the end to change it to be your current email address. When you send a new email, the default 'from' email address is picked up which will be your new one.
A time-out occurred while communicating with the server. Subject 'Re: New response to your discussion thread', Account: 'mail.btinternet.com', Server: 'mail.btinternet.com', Protocol: SMTP, Port: 25, Secure(SSL): No, Error Number: 0x800CCC19
This problem also occurs with my other email account.
All affected parties use BT 500plus broadband router, never quite sure if this means we are networked!
The green send status bar gets to the end and then just freezes before the above error message is displayed.
Bt, the b******s have changed their terms and conditions so that you cannot send mail via your own domain (i.e. you have got to send using a BT address) Surprise, surprise you can use your own mail server on payment of an extra monthly subscription.