CAN'T REPLY OR FORWARD

[Jeffrey]

I have 2 email addresses (with different ISPs) both operated through MS Outlook.

One of these is fine.  However, with the other email address, I cannot automatically reply or forward incoming messages.

What do you think is wrong and what can I try to correct?

[DaveLembke]

What ISP's?
Which Version of Outlook are you using?
Curious as to why you want to ( automatically ) reply or forward messages... unattended response system or relay point for one e-mail to come in to a specific e-mail address and then forward to another without exposing the second e-mail address etc?

[Jeffrey]

I'm using Outlook 12.0.67. The problem ISP is Waitrose Just Mail (= PlusNet). When I said 'automatically' I simply meant using the 'reply' or 'forward' buttons to generate an 'automatic' reply or forwarding email (rather than create a 'new' message)

[Rustys]

Are these the only 2 that is happens to and what is the error if any that you get?  does this happen with any message that you attempt to forward or reply to.

Have you checked the reply to address to make sure it is correct?

Try removing the address and manually add or use the address book see if the same thing happens.