i don't understand with command i will install zimbra opensource in redhat
i will use this command to build fetchmail

vim .fetchmailrc
set no bouncemail
set postmaster postmaster@example.com
set logfile /opt/zimbra/extlog/fetchmailrc.log
poll pop3.your-isp.com with protocol POP3, with options uidl
localdomains example.com
no dns
envelope "Envelope-to"
user "pop3user" there with password "pop3password" is *
with options rewrite fetchall

#build fetchmail log file
mkdir /opt/zimbra/extlog/
touch /opt/zimbra/fetchmailrc.log

i don't understand about question
1. user "pop3User" "pop3password" what is the meaning when i want to add other one what line to add it
2. envelope to want to use all user or one line to add
3. this command is correct or not for fetch mail from isp in ex. my isp is example.com