no worries mate...

Step one: changing the file AVAST4.INI
Open avast4.ini file in Notepad editor. You will find this file in the folder Data in your avast! installation folder, e.g. C:\Program Files\ALWIL Software\avast4\Data.
Find the section named [MailScanner]. Write these lines into this section (if they already exist, change them):
DefaultSmtpServer=smtp.server.com
DefaultPopServer=pop.server.com
DefaultImapServer=imap.server.com (only if you are using IMAP server for incoming mail).
Replace smtp.server.com by the address of the SMTP server you are using, e.g. smtp.tiscali.com. Do the same for POP (and IMAP) server (e.g. pop3.tiscali.com).
If your e-mail program supports SMTP authentication, and also makes it possible to set a different login name for SMTP than for POP, insert the line: UseDefaultSmtp=0.
If your e-mail program does not support SMTP authentication, insert the line: UseDefaultSmtp=1.
Save the changes and close the Notepad editor.
Step two: modifying the account properties in your mail program
Launch your mail program.
Let the program display the account settings.
If you want to check outgoing messages, change the address of SMTP server to the address of the local computer, i.e. 127.0.0.1.
If you want to check incoming messages, change the address of POP (IMAP) server to the address of the local computer, i.e. 127.0.0.1.
Change user (login) name this way: append the character # (double hash) and the address of your POP (IMAP) server (the same as you specified in the avast4.ini file in Step one). Login name should then look like this:
Ann.Jones#pop3.tiscali.com
If your e-mail program supports SMTP authentication and also makes it possible to set a different login name for SMTP than for POP
If the SMTP authentication is enabled, append the character # and the address of your SMTP server to the login name (e.g. annie2#smtp.tiscali.com).
If the SMTP authentication is disabled, enable it and use the character # together with the address of your SMTP server as the login name (e.g. #smtp.tiscali.com).
Save your changes.
The manual setting of the Mail scanner is now complete.
i got this fron the help files provided by avast...

hope it helps