Try to set this way:
Stunnel
# GMail
client=yes
# POP3 service, listens on localhost:11110
[gmail-pop3s]
accept=127.0.0.1:11110
connect=pop.gmail.com:995
# SMTP service, listens on localhost:11025
[gmail-smtps]
protocol=smtp
accept=127.0.0.1:11025
connect=smtp.gmail.com:587
avast settings (<Avast>\Data\Avast4.ini)
Section [MailScanner] you must have among other settings, these ones:
PopListen=127.0.0.1:110
SmtpListen=127.0.0.1:25
ImapListen=127.0.0.1:143
NntpListen=127.0.0.1:119
PopRedirectPort=110,120,11110
SmtpRedirectPort=25,11025
IgnoreLocalhost=0
Outlook Express settings
Pop3 server: 127.0.0.1
Smtp server: 127.0.0.1
Account name: <gmail name without @gmail.com>
smtp authorization: full gmailname@gmail.com and password
pop3 port: 11110 (uncheck SSL)
smtp port: 11025 (uncheck SSL)
Timeout: 5 minutes