What we experienced: Do not save any changed Mercury D settings when Mercury D is just retrieving mails or polling mailboxes. In that case Mercury is not taking over the changes. Our Mercury D is polling our 20 mailboxes every 120 seconds and I have to wait for the finish of such a polling cycle before using the SAVE button of Mercury D. Alternatively you could set Mercury in offline mode until you've made your changes.

I have not reconfigured for a few years and seem to have forgotten something!?

I put in my POP3 address (mail.hopkins.me.uk), "aidan@hopkins.me.uk" in user, POP3 password, then "aidan" in default user. I save the details but when I look again they are blank. I must be doing something daft?!

Any ideas much appreciated.

Details should be written to the file MERCURYD.DAT in the main Mercury folder. Check if the file exists and when it was last updated. If it's not there or not recently updated it would seem something is blocking access to it. 

Thanks very much - the file was missing. I found a backup copy and all is now working!

Cheers