Could you tell me if this is a bug or sommenthing else cause, with the last version, it was good !
I think it's not related to the changed servers but, anyway, yahoo have some trouble as it is not a pop3/smtp server as far I know. It I'm wrong, it should be a way to get your old configuration back using the value
AutoRedirect=0 in section [MailScanner] of avast4.ini file (see
here for more details).
If you use AutoRedirect=1 it will allow the automatic mail scanning as it is on avast 4.5 version. Note, if you use spam killer take care that localhost (or 127.0.0.1) connections are not scanned, i.e, the ones between the email program (e.g., Outlook Express) and the spam killer (e.g., MailWasher, K9 or Spamihilator), unless these connections were explicitly configured.
To switch off the automatic mail scan, set this value to 0, this should restore the old behavior (version 4.1) of the Mail protection and Mail Protection Wizard.